diff --git a/include/SkeletalTrapezoidationEdge.h b/include/SkeletalTrapezoidationEdge.h
index aa897d830f..4c0bfb365c 100644
--- a/include/SkeletalTrapezoidationEdge.h
+++ b/include/SkeletalTrapezoidationEdge.h
@@ -80,7 +80,7 @@ class SkeletalTrapezoidationEdge
     {
         return transitions.use_count() > 0 && (ignore_empty || ! transitions.lock()->empty());
     }
-    void setTransitions(std::shared_ptr<std::list<TransitionMiddle>> storage)
+    void setTransitions(std::shared_ptr<std::list<TransitionMiddle>>& storage)
     {
         transitions = storage;
     }
@@ -93,7 +93,7 @@ class SkeletalTrapezoidationEdge
     {
         return transition_ends.use_count() > 0 && (ignore_empty || ! transition_ends.lock()->empty());
     }
-    void setTransitionEnds(std::shared_ptr<std::list<TransitionEnd>> storage)
+    void setTransitionEnds(std::shared_ptr<std::list<TransitionEnd>>& storage)
     {
         transition_ends = storage;
     }
@@ -106,7 +106,7 @@ class SkeletalTrapezoidationEdge
     {
         return extrusion_junctions.use_count() > 0 && (ignore_empty || ! extrusion_junctions.lock()->empty());
     }
-    void setExtrusionJunctions(std::shared_ptr<LineJunctions> storage)
+    void setExtrusionJunctions(std::shared_ptr<LineJunctions>& storage)
     {
         extrusion_junctions = storage;
     }
diff --git a/include/SkeletalTrapezoidationJoint.h b/include/SkeletalTrapezoidationJoint.h
index 603b9b452f..7c7575a07b 100644
--- a/include/SkeletalTrapezoidationJoint.h
+++ b/include/SkeletalTrapezoidationJoint.h
@@ -43,7 +43,7 @@ class SkeletalTrapezoidationJoint
     {
         return beading.use_count() > 0;
     }
-    void setBeading(std::shared_ptr<BeadingPropagation> storage)
+    void setBeading(std::shared_ptr<BeadingPropagation>& storage)
     {
         beading = storage;
     }
diff --git a/include/infill.h b/include/infill.h
index 7c6a342499..40ca7fbd59 100644
--- a/include/infill.h
+++ b/include/infill.h
@@ -203,8 +203,8 @@ class Infill
         const Settings& settings,
         int layer_idx,
         SectionType section_type,
-        const std::shared_ptr<SierpinskiFillProvider> cross_fill_provider = nullptr,
-        const std::shared_ptr<LightningLayer> lightning_layer = nullptr,
+        const std::shared_ptr<SierpinskiFillProvider>& cross_fill_provider = nullptr,
+        const std::shared_ptr<LightningLayer>& lightning_layer = nullptr,
         const SliceMeshStorage* mesh = nullptr,
         const Polygons& prevent_small_exposed_to_air = Polygons(),
         const bool is_bridge_skin = false);
@@ -242,8 +242,8 @@ class Infill
         Polygons& result_polygons,
         Polygons& result_lines,
         const Settings& settings,
-        const std::shared_ptr<SierpinskiFillProvider> cross_fill_pattern = nullptr,
-        const std::shared_ptr<LightningLayer> lightning_layer = nullptr,
+        const std::shared_ptr<SierpinskiFillProvider>& cross_fill_pattern = nullptr,
+        const std::shared_ptr<LightningLayer>& lightning_layer = nullptr,
         const SliceMeshStorage* mesh = nullptr);
 
     /*!
@@ -402,7 +402,7 @@ class Infill
      * see https://hal.archives-ouvertes.fr/hal-02155929/document
      * \param result (output) The resulting polygons
      */
-    void generateLightningInfill(const std::shared_ptr<LightningLayer> lightning_layer, Polygons& result_lines);
+    void generateLightningInfill(const std::shared_ptr<LightningLayer>& lightning_layer, Polygons& result_lines);
 
     /*!
      * Generate sparse concentric infill
diff --git a/src/communication/ArcusCommunication.cpp b/src/communication/ArcusCommunication.cpp
index cf17d69454..44cc58cbe2 100644
--- a/src/communication/ArcusCommunication.cpp
+++ b/src/communication/ArcusCommunication.cpp
@@ -420,7 +420,7 @@ void ArcusCommunication::sendOptimizedLayerData()
     }
     spdlog::info("Sending {} layers.", data.current_layer_count);
 
-    for (std::pair<const int, std::shared_ptr<proto::LayerOptimized>> entry : data.slice_data) // Note: This is in no particular order!
+    for (const auto& entry : data.slice_data) // Note: This is in no particular order!
     {
         spdlog::debug("Sending layer data for layer {} of {}.", entry.first, data.slice_data.size());
         private_data->socket->sendMessage(entry.second); // Send the actual layers.
diff --git a/src/infill.cpp b/src/infill.cpp
index 6bdd545aaa..9137aa66ca 100644
--- a/src/infill.cpp
+++ b/src/infill.cpp
@@ -88,8 +88,8 @@ void Infill::generate(
     const Settings& settings,
     int layer_idx,
     SectionType section_type,
-    const std::shared_ptr<SierpinskiFillProvider> cross_fill_provider,
-    const std::shared_ptr<LightningLayer> lightning_trees,
+    const std::shared_ptr<SierpinskiFillProvider>& cross_fill_provider,
+    const std::shared_ptr<LightningLayer>& lightning_trees,
     const SliceMeshStorage* mesh,
     const Polygons& prevent_small_exposed_to_air,
     const bool is_bridge_skin)
@@ -255,8 +255,8 @@ void Infill::_generate(
     Polygons& result_polygons,
     Polygons& result_lines,
     const Settings& settings,
-    const std::shared_ptr<SierpinskiFillProvider> cross_fill_provider,
-    const std::shared_ptr<LightningLayer> lightning_trees,
+    const std::shared_ptr<SierpinskiFillProvider>& cross_fill_provider,
+    const std::shared_ptr<LightningLayer>& lightning_trees,
     const SliceMeshStorage* mesh)
 {
     if (inner_contour.empty())
@@ -432,7 +432,7 @@ void Infill::generateGyroidInfill(Polygons& result_lines, Polygons& result_polyg
     PolylineStitcher<Polygons, Polygon, Point>::stitch(line_segments, result_lines, result_polygons, infill_line_width);
 }
 
-void Infill::generateLightningInfill(const std::shared_ptr<LightningLayer> trees, Polygons& result_lines)
+void Infill::generateLightningInfill(const std::shared_ptr<LightningLayer>& trees, Polygons& result_lines)
 {
     // Don't need to support areas smaller than line width, as they are always within radius:
     if (std::abs(inner_contour.area()) < infill_line_width || ! trees)