diff --git a/platform/default/src/mbgl/storage/file_source_request.cpp b/platform/default/src/mbgl/storage/file_source_request.cpp
index 667cbf345..c8d5ae46a 100644
--- a/platform/default/src/mbgl/storage/file_source_request.cpp
+++ b/platform/default/src/mbgl/storage/file_source_request.cpp
@@ -24,7 +24,7 @@ void FileSourceRequest::onCancel(std::function<void()>&& callback) {
 void FileSourceRequest::setResponse(const Response& response) {
     // Copy, because calling the callback will sometimes self
     // destroy this object. We cannot move because this method
-    // can be called more than one.
+    // can be called more than once.
     auto callback = responseCallback;
     callback(response);
 }
diff --git a/src/mbgl/geometry/feature_index.cpp b/src/mbgl/geometry/feature_index.cpp
index 240c61136..d4fd47b30 100644
--- a/src/mbgl/geometry/feature_index.cpp
+++ b/src/mbgl/geometry/feature_index.cpp
@@ -33,6 +33,90 @@ mbgl::Point<double> project(const mbgl::LatLng& coordinate, const mbgl::Transfor
 
 namespace mbgl {
 
+constexpr auto expectedUniqueLayerIDs = 10;
+constexpr auto expectedUniqueLeaderIDs = 30;
+
+RefIndexedSubfeature::RefIndexedSubfeature(std::size_t index_,
+                                           const std::string& sourceLayerName_,
+                                           const std::string& bucketName_,
+                                           size_t sortIndex_,
+                                           uint32_t bucketInstanceId_,
+                                           uint16_t collisionGroupId_)
+    : index(index_),
+      sortIndex(sortIndex_),
+      sourceLayerName(sourceLayerName_),
+      bucketLeaderID(bucketName_),
+      bucketInstanceId(bucketInstanceId_),
+      collisionGroupId(collisionGroupId_) {}
+
+IndexedSubfeature::IndexedSubfeature(const RefIndexedSubfeature& other)
+    : IndexedSubfeature(other, other.getBucketInstanceId(), other.getCollisionGroupId()) {}
+
+IndexedSubfeature::IndexedSubfeature(const RefIndexedSubfeature& other,
+                                     uint32_t bucketInstanceId_,
+                                     uint16_t collisionGroupId_)
+    : IndexedSubfeature(other.getIndex(),
+                        other.getSourceLayerName(),
+                        other.getBucketLeaderID(),
+                        other.getSortIndex(),
+                        bucketInstanceId_,
+                        collisionGroupId_) {}
+
+IndexedSubfeature::IndexedSubfeature(const IndexedSubfeature& other)
+    : IndexedSubfeature(other.getIndex(),
+                        other.sourceLayerName,
+                        other.bucketLeaderID,
+                        other.getSortIndex(),
+                        other.getBucketInstanceId(),
+                        other.getCollisionGroupId()) {}
+
+IndexedSubfeature::IndexedSubfeature(IndexedSubfeature&& other)
+    : IndexedSubfeature(other.getIndex(),
+                        std::move(other.sourceLayerName),
+                        std::move(other.bucketLeaderID),
+                        other.getSortIndex(),
+                        other.getBucketInstanceId(),
+                        other.getCollisionGroupId()) {}
+
+IndexedSubfeature::IndexedSubfeature(std::size_t index_,
+                                     std::string sourceLayerName_,
+                                     std::string bucketName_,
+                                     size_t sortIndex_,
+                                     uint32_t bucketInstanceId_,
+                                     uint16_t collisionGroupId_)
+    : RefIndexedSubfeature(index_,
+                           this->sourceLayerNameCopy,
+                           this->bucketLeaderIDCopy,
+                           sortIndex_,
+                           bucketInstanceId_,
+                           collisionGroupId_),
+      sourceLayerNameCopy(std::move(sourceLayerName_)),
+      bucketLeaderIDCopy(std::move(bucketName_)) {}
+
+IndexedSubfeature& IndexedSubfeature::operator=(const IndexedSubfeature& other) {
+    index = other.index;
+    sourceLayerName = sourceLayerNameCopy;
+    bucketLeaderID = bucketLeaderIDCopy;
+    sortIndex = other.sortIndex;
+    bucketInstanceId = other.bucketInstanceId;
+    collisionGroupId = other.collisionGroupId;
+    sourceLayerNameCopy = other.sourceLayerNameCopy;
+    bucketLeaderIDCopy = other.bucketLeaderIDCopy;
+    return *this;
+}
+
+IndexedSubfeature& IndexedSubfeature::operator=(IndexedSubfeature&& other) {
+    index = other.index;
+    sourceLayerName = sourceLayerNameCopy;
+    bucketLeaderID = bucketLeaderIDCopy;
+    sortIndex = other.sortIndex;
+    bucketInstanceId = other.bucketInstanceId;
+    collisionGroupId = other.collisionGroupId;
+    sourceLayerNameCopy = std::move(other.sourceLayerNameCopy);
+    bucketLeaderIDCopy = std::move(other.bucketLeaderIDCopy);
+    return *this;
+}
+
 FeatureIndex::FeatureIndex(std::unique_ptr<const GeometryTileData> tileData_)
     : grid(util::EXTENT, util::EXTENT, util::EXTENT / 16), // 16x16 grid -> 32px cell
       tileData(std::move(tileData_)) {}
@@ -41,12 +125,22 @@ void FeatureIndex::insert(const GeometryCollection& geometries,
                           std::size_t index,
                           const std::string& sourceLayerName,
                           const std::string& bucketLeaderID) {
+    if (uniqueLayerIDs.empty()) {
+        uniqueLayerIDs.reserve(expectedUniqueLayerIDs);
+    }
+    const std::string& emplacedLayerName = *uniqueLayerIDs.insert(sourceLayerName).first;
+    if (bucketLayerIDs.empty()) {
+        bucketLayerIDs.reserve(expectedUniqueLeaderIDs);
+    }
+    const std::string& emplacedLeaderID =
+        bucketLayerIDs.insert(std::make_pair(bucketLeaderID, std::vector<std::string>{})).first->first;
+
     auto featureSortIndex = sortIndex++;
     for (const auto& ring : geometries) {
-        auto envelope = mapbox::geometry::envelope(ring);
+        const auto envelope = mapbox::geometry::envelope(ring);
         if (envelope.min.x < util::EXTENT && envelope.min.y < util::EXTENT && envelope.max.x >= 0 &&
             envelope.max.y >= 0) {
-            grid.insert(IndexedSubfeature(index, sourceLayerName, bucketLeaderID, featureSortIndex),
+            grid.insert(RefIndexedSubfeature(index, emplacedLayerName, emplacedLeaderID, featureSortIndex),
                         {convertPoint<float>(envelope.min), convertPoint<float>(envelope.max)});
         }
     }
@@ -74,17 +168,17 @@ void FeatureIndex::query(std::unordered_map<std::string, std::vector<Feature>>&
 
     // Query the grid index
     mapbox::geometry::box<int16_t> box = mapbox::geometry::envelope(queryGeometry);
-    std::vector<IndexedSubfeature> features = grid.query(
+    std::vector<RefIndexedSubfeature> features = grid.query(
         {convertPoint<float>(box.min - additionalPadding), convertPoint<float>(box.max + additionalPadding)});
 
-    std::sort(features.begin(), features.end(), [](const IndexedSubfeature& a, const IndexedSubfeature& b) {
-        return a.sortIndex > b.sortIndex;
+    std::sort(features.begin(), features.end(), [](const RefIndexedSubfeature& a, const RefIndexedSubfeature& b) {
+        return a.getSortIndex() > b.getSortIndex();
     });
     size_t previousSortIndex = std::numeric_limits<size_t>::max();
     for (const auto& indexedFeature : features) {
         // If this feature is the same as the previous feature, skip it.
-        if (indexedFeature.sortIndex == previousSortIndex) continue;
-        previousSortIndex = indexedFeature.sortIndex;
+        if (indexedFeature.getSortIndex() == previousSortIndex) continue;
+        previousSortIndex = indexedFeature.getSortIndex();
 
         addFeature(result,
                    indexedFeature,
@@ -109,11 +203,12 @@ std::unordered_map<std::string, std::vector<Feature>> FeatureIndex::lookupSymbol
     if (!tileData) {
         return result;
     }
-    std::vector<IndexedSubfeature> sortedFeatures(symbolFeatures.begin(), symbolFeatures.end());
+    std::vector<std::reference_wrapper<const RefIndexedSubfeature>> sortedFeatures(symbolFeatures.begin(),
+                                                                                   symbolFeatures.end());
 
     std::sort(sortedFeatures.begin(),
               sortedFeatures.end(),
-              [featureSortOrder](const IndexedSubfeature& a, const IndexedSubfeature& b) {
+              [featureSortOrder](const RefIndexedSubfeature& a, const RefIndexedSubfeature& b) {
                   // Same idea as the non-symbol sort order, but symbol features may
                   // have changed their sort order since their corresponding
                   // IndexedSubfeature was added to the CollisionIndex The
@@ -124,15 +219,15 @@ std::unordered_map<std::string, std::vector<Feature>> FeatureIndex::lookupSymbol
                       // "top-to-bottom" rendering order (aka last-to-first).
                       // Actually there can be multiple symbol instances per feature, so
                       // we sort each feature based on the first matching symbol instance.
-                      auto sortedA = std::find(featureSortOrder->begin(), featureSortOrder->end(), a.index);
-                      auto sortedB = std::find(featureSortOrder->begin(), featureSortOrder->end(), b.index);
+                      auto sortedA = std::find(featureSortOrder->begin(), featureSortOrder->end(), a.getIndex());
+                      auto sortedB = std::find(featureSortOrder->begin(), featureSortOrder->end(), b.getIndex());
                       assert(sortedA != featureSortOrder->end());
                       assert(sortedB != featureSortOrder->end());
                       return sortedA > sortedB;
                   } else {
                       // Bucket hasn't been re-sorted based on angle, so use same
                       // "reverse of appearance in source data" logic as non-symboles
-                      return a.sortIndex > b.sortIndex;
+                      return a.getSortIndex() > b.getSortIndex();
                   }
               });
 
@@ -153,7 +248,7 @@ std::unordered_map<std::string, std::vector<Feature>> FeatureIndex::lookupSymbol
 }
 
 void FeatureIndex::addFeature(std::unordered_map<std::string, std::vector<Feature>>& result,
-                              const IndexedSubfeature& indexedFeature,
+                              const RefIndexedSubfeature& indexedFeature,
                               const RenderedQueryOptions& options,
                               const CanonicalTileID& tileID,
                               const std::unordered_map<std::string, const RenderLayer*>& layers,
@@ -166,7 +261,7 @@ void FeatureIndex::addFeature(std::unordered_map<std::string, std::vector<Featur
     std::unique_ptr<GeometryTileLayer> sourceLayer;
     std::unique_ptr<GeometryTileFeature> geometryTileFeature;
 
-    for (const std::string& layerID : bucketLayerIDs.at(indexedFeature.bucketLeaderID)) {
+    for (const std::string& layerID : bucketLayerIDs.at(indexedFeature.getBucketLeaderID())) {
         const auto it = layers.find(layerID);
         if (it == layers.end()) {
             continue;
@@ -175,10 +270,10 @@ void FeatureIndex::addFeature(std::unordered_map<std::string, std::vector<Featur
         const RenderLayer* renderLayer = it->second;
 
         if (!geometryTileFeature) {
-            sourceLayer = tileData->getLayer(indexedFeature.sourceLayerName);
+            sourceLayer = tileData->getLayer(indexedFeature.getSourceLayerName());
             assert(sourceLayer);
 
-            geometryTileFeature = sourceLayer->getFeature(indexedFeature.index);
+            geometryTileFeature = sourceLayer->getFeature(indexedFeature.getIndex());
             assert(geometryTileFeature);
         }
         FeatureState state;
@@ -226,6 +321,8 @@ std::optional<GeometryCoordinates> FeatureIndex::translateQueryGeometry(const Ge
     }
 
     GeometryCoordinates translated;
+    translated.reserve(queryGeometry.size());
+
     for (const auto& p : queryGeometry) {
         translated.push_back(p - translateVec);
     }
@@ -233,6 +330,9 @@ std::optional<GeometryCoordinates> FeatureIndex::translateQueryGeometry(const Ge
 }
 
 void FeatureIndex::setBucketLayerIDs(const std::string& bucketLeaderID, const std::vector<std::string>& layerIDs) {
+    if (bucketLayerIDs.empty()) {
+        bucketLayerIDs.reserve(expectedUniqueLeaderIDs);
+    }
     bucketLayerIDs[bucketLeaderID] = layerIDs;
 }
 
@@ -249,6 +349,7 @@ void DynamicFeatureIndex::query(std::unordered_map<std::string, std::vector<Feat
         const Point<int64_t> coord = {int64_t(pm.x), int64_t(pm.y)};
         mbgl::updateBBox(queryBox, coord);
     }
+
     for (const auto& f : features) {
         // hit testing
         mbgl::GeometryBBox<int64_t> featureBox = DefaultWithinBBox;
diff --git a/src/mbgl/geometry/feature_index.hpp b/src/mbgl/geometry/feature_index.hpp
index 01aa6d505..2b7c02a60 100644
--- a/src/mbgl/geometry/feature_index.hpp
+++ b/src/mbgl/geometry/feature_index.hpp
@@ -21,34 +21,69 @@ class SourceFeatureState;
 
 class CollisionIndex;
 
-class IndexedSubfeature {
+/// An indexed element within a feature index.
+/// This version holds a reference to the strings within the index itself to avoid making tens of thousands of
+/// unnecessary copies of them. As a result, its lifetime cannot exceed that of the index.
+class RefIndexedSubfeature {
 public:
-    IndexedSubfeature() = delete;
-    IndexedSubfeature(std::size_t index_, std::string sourceLayerName_, std::string bucketName_, size_t sortIndex_)
-        : index(index_),
-          sourceLayerName(std::move(sourceLayerName_)),
-          bucketLeaderID(std::move(bucketName_)),
-          sortIndex(sortIndex_),
-          bucketInstanceId(0),
-          collisionGroupId(0) {}
+    RefIndexedSubfeature() = delete;
+    RefIndexedSubfeature(RefIndexedSubfeature&&) = default;
+    RefIndexedSubfeature(const RefIndexedSubfeature&) = default;
+    RefIndexedSubfeature(std::size_t index_,
+                         const std::string& sourceLayerName_,
+                         const std::string& bucketName_,
+                         size_t sortIndex_,
+                         uint32_t bucketInstanceId_ = 0,
+                         uint16_t collisionGroupId_ = 0);
 
-    IndexedSubfeature(const IndexedSubfeature& other, uint32_t bucketInstanceId_, uint16_t collisionGroupId_)
-        : index(other.index),
-          sourceLayerName(other.sourceLayerName),
-          bucketLeaderID(other.bucketLeaderID),
-          sortIndex(other.sortIndex),
-          bucketInstanceId(bucketInstanceId_),
-          collisionGroupId(collisionGroupId_) {}
+    RefIndexedSubfeature& operator=(const RefIndexedSubfeature&) = default;
+    RefIndexedSubfeature& operator=(RefIndexedSubfeature&&) = default;
+
+    size_t getIndex() const { return index; }
+    size_t getSortIndex() const { return sortIndex; }
+
+    const std::string& getSourceLayerName() const { return sourceLayerName.get(); }
+    const std::string& getBucketLeaderID() const { return bucketLeaderID.get(); }
+
+    uint32_t getBucketInstanceId() const { return bucketInstanceId; }
+    uint16_t getCollisionGroupId() const { return collisionGroupId; }
+
+protected:
     size_t index;
-    std::string sourceLayerName;
-    std::string bucketLeaderID;
     size_t sortIndex;
 
+    std::reference_wrapper<const std::string> sourceLayerName;
+    std::reference_wrapper<const std::string> bucketLeaderID;
+
     // Only used for symbol features
     uint32_t bucketInstanceId;
     uint16_t collisionGroupId;
 };
 
+/// This version of an indexed feature has copies of the necessary strings, so that it can be used outside the index.
+class IndexedSubfeature : public RefIndexedSubfeature {
+public:
+    IndexedSubfeature(const RefIndexedSubfeature&);
+    IndexedSubfeature(const RefIndexedSubfeature&, uint32_t bucketInstanceId_, uint16_t collisionGroupId_);
+
+    IndexedSubfeature(const IndexedSubfeature&);
+    IndexedSubfeature(IndexedSubfeature&&);
+
+    IndexedSubfeature(std::size_t index_,
+                      std::string sourceLayerName_,
+                      std::string bucketName_,
+                      size_t sortIndex_,
+                      uint32_t bucketInstanceId_ = 0,
+                      uint16_t collisionGroupId_ = 0);
+
+    IndexedSubfeature& operator=(const IndexedSubfeature&);
+    IndexedSubfeature& operator=(IndexedSubfeature&&);
+
+private:
+    std::string sourceLayerNameCopy;
+    std::string bucketLeaderIDCopy;
+};
+
 using FeatureSortOrder = std::shared_ptr<const std::vector<size_t>>;
 
 class DynamicFeatureIndex {
@@ -112,7 +147,7 @@ public:
 
 private:
     void addFeature(std::unordered_map<std::string, std::vector<Feature>>& result,
-                    const IndexedSubfeature&,
+                    const RefIndexedSubfeature&,
                     const RenderedQueryOptions& options,
                     const CanonicalTileID&,
                     const std::unordered_map<std::string, const RenderLayer*>&,
@@ -122,10 +157,15 @@ private:
                     const mat4& posMatrix,
                     const SourceFeatureState* sourceFeatureState) const;
 
-    GridIndex<IndexedSubfeature> grid;
+    GridIndex<RefIndexedSubfeature> grid;
     unsigned int sortIndex = 0;
 
+    // mbgl::unordered_* cannot be used here, as we rely on holding references to elements:
+    //     22.2.7 Unordered associative containers [unord.req]
+    //     The insert and emplace members shall not affect the validity of references to
+    //     container elements, but may invalidate all iterators to the container.
     std::unordered_map<std::string, std::vector<std::string>> bucketLayerIDs;
+    std::unordered_set<std::string> uniqueLayerIDs;
     std::unique_ptr<const GeometryTileData> tileData;
 };
 } // namespace mbgl
diff --git a/src/mbgl/layout/symbol_instance.cpp b/src/mbgl/layout/symbol_instance.cpp
index 9b48b0de2..024479566 100644
--- a/src/mbgl/layout/symbol_instance.cpp
+++ b/src/mbgl/layout/symbol_instance.cpp
@@ -87,7 +87,7 @@ SymbolInstance::SymbolInstance(Anchor& anchor_,
                                const float iconBoxScale,
                                const float iconPadding,
                                const std::array<float, 2>& iconOffset_,
-                               const IndexedSubfeature& indexedFeature,
+                               const RefIndexedSubfeature& indexedFeature,
                                const std::size_t layoutFeatureIndex_,
                                const std::size_t dataFeatureIndex_,
                                std::u16string key_,
diff --git a/src/mbgl/layout/symbol_instance.hpp b/src/mbgl/layout/symbol_instance.hpp
index 2082b6d2a..3d57d1d71 100644
--- a/src/mbgl/layout/symbol_instance.hpp
+++ b/src/mbgl/layout/symbol_instance.hpp
@@ -66,7 +66,7 @@ public:
                    float iconBoxScale,
                    float iconPadding,
                    const std::array<float, 2>& iconOffset,
-                   const IndexedSubfeature& indexedFeature,
+                   const RefIndexedSubfeature& indexedFeature,
                    std::size_t layoutFeatureIndex,
                    std::size_t dataFeatureIndex,
                    std::u16string key,
diff --git a/src/mbgl/renderer/layers/render_symbol_layer.cpp b/src/mbgl/renderer/layers/render_symbol_layer.cpp
index cadb9d2f3..9a8af217d 100644
--- a/src/mbgl/renderer/layers/render_symbol_layer.cpp
+++ b/src/mbgl/renderer/layers/render_symbol_layer.cpp
@@ -1206,13 +1206,15 @@ void RenderSymbolLayer::update(gfx::ShaderRegistry& shaders,
 
     // We'll be processing renderables across tiles, potentially out-of-order, so keep
     // track of some things by tile ID so we don't have to re-build them multiple times.
-    using RawVertexVec = std::vector<std::uint8_t>; // <int16_t, 4>
+    using RawVertexVec = std::vector<std::uint8_t>; // raw buffer for vertexes of <int16_t, 4>
     struct TileInfo {
         RawVertexVec textVertices, iconVertices;
         gfx::DrawableTweakerPtr textTweaker, iconTweaker;
         gfx::UniformBufferPtr textInterp, iconInterp;
     };
+
     std::unordered_map<UnwrappedTileID, TileInfo> tileCache;
+    tileCache.reserve(renderTiles->size());
 
     for (auto& group : renderableSegments) {
         const auto& renderable = group.renderable;
diff --git a/src/mbgl/text/collision_feature.hpp b/src/mbgl/text/collision_feature.hpp
index dd272a48d..29f63ac25 100644
--- a/src/mbgl/text/collision_feature.hpp
+++ b/src/mbgl/text/collision_feature.hpp
@@ -87,7 +87,7 @@ public:
                      const float boxScale,
                      const float padding,
                      const style::SymbolPlacementType placement,
-                     const IndexedSubfeature& indexedFeature_,
+                     const RefIndexedSubfeature& indexedFeature_,
                      const float overscaling,
                      const float rotate)
         : CollisionFeature(line,
@@ -117,7 +117,7 @@ public:
                      std::optional<PositionedIcon> shapedIcon,
                      const float boxScale,
                      const float padding,
-                     const IndexedSubfeature& indexedFeature_,
+                     const RefIndexedSubfeature& indexedFeature_,
                      const float rotate)
         : CollisionFeature(line,
                            anchor,
diff --git a/src/mbgl/text/collision_index.cpp b/src/mbgl/text/collision_index.cpp
index 3a7512150..c4d318087 100644
--- a/src/mbgl/text/collision_index.cpp
+++ b/src/mbgl/text/collision_index.cpp
@@ -159,7 +159,7 @@ std::pair<bool, bool> CollisionIndex::placeFeature(
     const bool pitchWithMap,
     const bool collisionDebug,
     const std::optional<CollisionBoundaries>& avoidEdges,
-    const std::optional<std::function<bool(const IndexedSubfeature&)>>& collisionGroupPredicate,
+    const std::optional<std::function<bool(const RefIndexedSubfeature&)>>& collisionGroupPredicate,
     std::vector<ProjectedCollisionBox>& projectedBoxes) {
     assert(projectedBoxes.empty());
     if (!feature.alongLine) {
@@ -202,7 +202,7 @@ std::pair<bool, bool> CollisionIndex::placeLineFeature(
     const bool pitchWithMap,
     const bool collisionDebug,
     const std::optional<CollisionBoundaries>& avoidEdges,
-    const std::optional<std::function<bool(const IndexedSubfeature&)>>& collisionGroupPredicate,
+    const std::optional<std::function<bool(const RefIndexedSubfeature&)>>& collisionGroupPredicate,
     std::vector<ProjectedCollisionBox>& projectedBoxes) {
     assert(feature.alongLine);
     assert(projectedBoxes.empty());
@@ -340,10 +340,10 @@ void CollisionIndex::insertFeature(const CollisionFeature& feature,
             }
 
             if (ignorePlacement) {
-                ignoredGrid.insert(IndexedSubfeature(feature.indexedFeature, bucketInstanceId, collisionGroupId),
+                ignoredGrid.insert(IndexedSubfeature{feature.indexedFeature, bucketInstanceId, collisionGroupId},
                                    circle.circle());
             } else {
-                collisionGrid.insert(IndexedSubfeature(feature.indexedFeature, bucketInstanceId, collisionGroupId),
+                collisionGrid.insert(IndexedSubfeature{feature.indexedFeature, bucketInstanceId, collisionGroupId},
                                      circle.circle());
             }
         }
@@ -352,10 +352,10 @@ void CollisionIndex::insertFeature(const CollisionFeature& feature,
         auto& box = projectedBoxes[0];
         assert(box.isBox());
         if (ignorePlacement) {
-            ignoredGrid.insert(IndexedSubfeature(feature.indexedFeature, bucketInstanceId, collisionGroupId),
+            ignoredGrid.insert(IndexedSubfeature{feature.indexedFeature, bucketInstanceId, collisionGroupId},
                                box.box());
         } else {
-            collisionGrid.insert(IndexedSubfeature(feature.indexedFeature, bucketInstanceId, collisionGroupId),
+            collisionGrid.insert(IndexedSubfeature{feature.indexedFeature, bucketInstanceId, collisionGroupId},
                                  box.box());
         }
     }
@@ -398,23 +398,25 @@ std::unordered_map<uint32_t, std::vector<IndexedSubfeature>> CollisionIndex::que
 
     std::vector<QueryResult> features = collisionGrid.queryWithBoxes(envelope);
     std::vector<QueryResult> ignoredFeatures = ignoredGrid.queryWithBoxes(envelope);
-    features.insert(features.end(), ignoredFeatures.begin(), ignoredFeatures.end());
+    features.insert(features.end(),
+                    std::make_move_iterator(ignoredFeatures.begin()),
+                    std::make_move_iterator(ignoredFeatures.end()));
 
-    std::unordered_map<uint32_t, std::unordered_set<size_t>> seenBuckets;
+    mbgl::unordered_map<uint32_t, mbgl::unordered_set<size_t>> seenBuckets;
     for (auto& queryResult : features) {
         auto& feature = queryResult.first;
         auto& bbox = queryResult.second;
 
         // Skip already seen features.
-        auto& seenFeatures = seenBuckets[feature.bucketInstanceId];
-        if (seenFeatures.find(feature.index) != seenFeatures.end()) continue;
+        auto& seenFeatures = seenBuckets[feature.getBucketInstanceId()];
+        if (seenFeatures.find(feature.getIndex()) != seenFeatures.end()) continue;
 
         if (!polygonIntersectsBox(gridQuery, bbox)) {
             continue;
         }
 
-        seenFeatures.insert(feature.index);
-        result[feature.bucketInstanceId].push_back(feature);
+        seenFeatures.insert(feature.getIndex());
+        result[feature.getBucketInstanceId()].push_back(feature);
     }
 
     return result;
diff --git a/src/mbgl/text/collision_index.hpp b/src/mbgl/text/collision_index.hpp
index ef11a660d..776e626e7 100644
--- a/src/mbgl/text/collision_index.hpp
+++ b/src/mbgl/text/collision_index.hpp
@@ -48,7 +48,7 @@ public:
         bool pitchWithMap,
         bool collisionDebug,
         const std::optional<CollisionBoundaries>& avoidEdges,
-        const std::optional<std::function<bool(const IndexedSubfeature&)>>& collisionGroupPredicate,
+        const std::optional<std::function<bool(const RefIndexedSubfeature&)>>& collisionGroupPredicate,
         std::vector<ProjectedCollisionBox>& /*out*/
     );
 
@@ -84,7 +84,7 @@ private:
         bool pitchWithMap,
         bool collisionDebug,
         const std::optional<CollisionBoundaries>& avoidEdges,
-        const std::optional<std::function<bool(const IndexedSubfeature&)>>& collisionGroupPredicate,
+        const std::optional<std::function<bool(const RefIndexedSubfeature&)>>& collisionGroupPredicate,
         std::vector<ProjectedCollisionBox>& /*out*/
     );
 
diff --git a/src/mbgl/text/placement.cpp b/src/mbgl/text/placement.cpp
index e42b817d5..00148856a 100644
--- a/src/mbgl/text/placement.cpp
+++ b/src/mbgl/text/placement.cpp
@@ -49,8 +49,8 @@ const CollisionGroups::CollisionGroup& CollisionGroups::get(const std::string& s
             collisionGroups.emplace(
                 sourceID,
                 CollisionGroup(nextGroupID,
-                               std::optional<Predicate>([nextGroupID](const IndexedSubfeature& feature) -> bool {
-                                   return feature.collisionGroupId == nextGroupID;
+                               std::optional<Predicate>([nextGroupID](const RefIndexedSubfeature& feature) -> bool {
+                                   return feature.getCollisionGroupId() == nextGroupID;
                                })));
         }
         return collisionGroups[sourceID];
diff --git a/src/mbgl/text/placement.hpp b/src/mbgl/text/placement.hpp
index d04a927b0..8fb3f11f4 100644
--- a/src/mbgl/text/placement.hpp
+++ b/src/mbgl/text/placement.hpp
@@ -77,7 +77,7 @@ struct RetainedQueryData {
 
 class CollisionGroups {
 public:
-    using Predicate = std::function<bool(const IndexedSubfeature&)>;
+    using Predicate = std::function<bool(const RefIndexedSubfeature&)>;
     using CollisionGroup = std::pair<uint16_t, std::optional<Predicate>>;
 
     CollisionGroups(const bool crossSourceCollisions_)
diff --git a/src/mbgl/tile/geometry_tile_worker.cpp b/src/mbgl/tile/geometry_tile_worker.cpp
index 11bcf9631..5f23cffb9 100644
--- a/src/mbgl/tile/geometry_tile_worker.cpp
+++ b/src/mbgl/tile/geometry_tile_worker.cpp
@@ -363,7 +363,9 @@ void GeometryTileWorker::parse() {
     ImageDependencies imageDependencies;
 
     // Create render layers and group by layout
-    std::unordered_map<std::string, std::vector<Immutable<style::LayerProperties>>> groupMap;
+    mbgl::unordered_map<std::string, std::vector<Immutable<style::LayerProperties>>> groupMap;
+    groupMap.reserve(layers->size());
+
     for (auto layer : *layers) {
         groupMap[layoutKey(*layer->baseImpl)].push_back(std::move(layer));
     }
diff --git a/src/mbgl/util/grid_index.cpp b/src/mbgl/util/grid_index.cpp
index a5b704c2d..7adb6d2c3 100644
--- a/src/mbgl/util/grid_index.cpp
+++ b/src/mbgl/util/grid_index.cpp
@@ -3,6 +3,6 @@
 
 namespace mbgl {
 
-template class GridIndex<IndexedSubfeature>;
+template class GridIndex<RefIndexedSubfeature>;
 
 } // namespace mbgl
diff --git a/src/mbgl/util/grid_index.hpp b/src/mbgl/util/grid_index.hpp
index f7426e4b8..729b612dc 100644
--- a/src/mbgl/util/grid_index.hpp
+++ b/src/mbgl/util/grid_index.hpp
@@ -141,7 +141,7 @@ void GridIndex<T>::insert(T&& t, const BBox& bbox) {
         }
     }
 
-    boxElements.emplace_back(t, bbox);
+    boxElements.emplace_back(std::move(t), bbox);
 }
 
 template <class T>
@@ -164,7 +164,7 @@ void GridIndex<T>::insert(T&& t, const BCircle& bcircle) {
         }
     }
 
-    circleElements.emplace_back(t, bcircle);
+    circleElements.emplace_back(std::move(t), bcircle);
 }
 
 template <class T>
diff --git a/test/text/cross_tile_symbol_index.test.cpp b/test/text/cross_tile_symbol_index.test.cpp
index b9377ba76..3f3ccf3d7 100644
--- a/test/text/cross_tile_symbol_index.test.cpp
+++ b/test/text/cross_tile_symbol_index.test.cpp
@@ -10,7 +10,7 @@ SymbolInstance makeSymbolInstance(float x, float y, std::u16string key) {
     ImageMap imageMap;
     const ShapedTextOrientations shaping{};
     style::SymbolLayoutProperties::Evaluated layout_;
-    IndexedSubfeature subfeature(0, "", "", 0);
+    IndexedSubfeature subfeature(0, {}, {}, 0);
     Anchor anchor(x, y, 0, 0);
     std::array<float, 2> textOffset{{0.0f, 0.0f}};
     std::array<float, 2> iconOffset{{0.0f, 0.0f}};