diff --git a/.clang-tidy b/.clang-tidy
index b0398498e..566fa5b22 100644
--- a/.clang-tidy
+++ b/.clang-tidy
@@ -19,7 +19,8 @@ Checks: >
   -readability-use-anyofallof,
   -readability-redundant-access-specifiers,
   -readability-convert-member-functions-to-static,
-  -cppcoreguidelines-avoid-const-or-ref-data-members
+  -cppcoreguidelines-avoid-const-or-ref-data-members,
+  -cppcoreguidelines-pro-bounds-constant-array-index
 
 CheckOptions:
   - key: misc-non-private-member-variables-in-classes.IgnoreClassesWithAllMemberVariablesBeingPublic
diff --git a/include/geode/basic/mapping.hpp b/include/geode/basic/mapping.hpp
index fb520cb3b..afbfa8dd1 100644
--- a/include/geode/basic/mapping.hpp
+++ b/include/geode/basic/mapping.hpp
@@ -23,7 +23,8 @@
 
 #pragma once
 
-#include <absl/container/flat_hash_map.h>
+#include <absl/algorithm/container.h>
+#include <absl/container/btree_map.h>
 #include <absl/container/inlined_vector.h>
 
 #include <geode/basic/common.hpp>
@@ -39,7 +40,7 @@ namespace geode
         template < typename T >
         using Storage = typename StorageType< T >::Type;
 
-        void reserve( index_t capacity )
+        [[deprecated]] void reserve( index_t capacity )
         {
             in2out_.reserve( capacity );
             out2in_.reserve( capacity );
@@ -71,13 +72,13 @@ namespace geode
             return out2in_.at( out );
         }
 
-        [[nodiscard]] const absl::flat_hash_map< T1, Storage< T2 > >&
+        [[nodiscard]] const absl::btree_map< T1, Storage< T2 > >&
             in2out_map() const
         {
             return in2out_;
         }
 
-        [[nodiscard]] const absl::flat_hash_map< T2, Storage< T1 > >&
+        [[nodiscard]] const absl::btree_map< T2, Storage< T1 > >&
             out2in_map() const
         {
             return out2in_;
@@ -100,19 +101,19 @@ namespace geode
             return static_cast< index_t >( out2in_.size() );
         }
 
-        [[nodiscard]] absl::flat_hash_map< T1, Storage< T2 > >& in2out_mapping()
+        [[nodiscard]] absl::btree_map< T1, Storage< T2 > >& in2out_mapping()
         {
             return in2out_;
         }
 
-        [[nodiscard]] absl::flat_hash_map< T2, Storage< T1 > >& out2in_mapping()
+        [[nodiscard]] absl::btree_map< T2, Storage< T1 > >& out2in_mapping()
         {
             return out2in_;
         }
 
     private:
-        absl::flat_hash_map< T1, Storage< T2 > > in2out_;
-        absl::flat_hash_map< T2, Storage< T1 > > out2in_;
+        absl::btree_map< T1, Storage< T2 > > in2out_;
+        absl::btree_map< T2, Storage< T1 > > out2in_;
     };
 
     template < typename T >
@@ -225,6 +226,10 @@ namespace geode
             }
             auto& out_map = this->out2in_mapping().at( out );
             const auto itr2 = absl::c_find( out_map, in );
+            if( itr2 == out_map.end() )
+            {
+                return;
+            }
             out_map.erase( itr2 );
             if( this->out2in( out ).empty() )
             {
diff --git a/include/geode/model/mixin/core/component_type.hpp b/include/geode/model/mixin/core/component_type.hpp
index 41b99333e..0a27d659b 100644
--- a/include/geode/model/mixin/core/component_type.hpp
+++ b/include/geode/model/mixin/core/component_type.hpp
@@ -84,6 +84,15 @@ namespace geode
             return type_.get() == other.type_.get() && id_ == other.id_;
         }
 
+        [[nodiscard]] bool operator<( const ComponentID& other ) const
+        {
+            if( type_.get() != other.type_.get() )
+            {
+                return type_.get() < other.type_.get();
+            }
+            return id_ < other.id_;
+        }
+
         [[nodiscard]] std::string string() const
         {
             return absl::StrCat( type_.get(), " ", id_.string() );
diff --git a/include/geode/model/mixin/core/vertex_identifier.hpp b/include/geode/model/mixin/core/vertex_identifier.hpp
index 5d7e03be3..324408fe9 100644
--- a/include/geode/model/mixin/core/vertex_identifier.hpp
+++ b/include/geode/model/mixin/core/vertex_identifier.hpp
@@ -57,6 +57,8 @@ namespace geode
 
         [[nodiscard]] bool operator==( const ComponentMeshVertex& other ) const;
 
+        [[nodiscard]] bool operator<( const ComponentMeshVertex& other ) const;
+
         template < typename Archive >
         void serialize( Archive& archive );
 
diff --git a/src/geode/mesh/helpers/convert_surface_mesh.cpp b/src/geode/mesh/helpers/convert_surface_mesh.cpp
index 645948cc3..8da322e02 100644
--- a/src/geode/mesh/helpers/convert_surface_mesh.cpp
+++ b/src/geode/mesh/helpers/convert_surface_mesh.cpp
@@ -23,6 +23,8 @@
 
 #include <geode/mesh/helpers/convert_surface_mesh.hpp>
 
+#include <absl/container/flat_hash_map.h>
+
 #include <geode/basic/attribute_manager.hpp>
 #include <geode/basic/logger.hpp>
 
diff --git a/src/geode/mesh/helpers/detail/split_along_solid_facets.cpp b/src/geode/mesh/helpers/detail/split_along_solid_facets.cpp
index e458e109a..bde7de751 100644
--- a/src/geode/mesh/helpers/detail/split_along_solid_facets.cpp
+++ b/src/geode/mesh/helpers/detail/split_along_solid_facets.cpp
@@ -139,7 +139,6 @@ namespace geode
             ElementsMapping duplicate_points( const SolidInfo& solid_info )
             {
                 ElementsMapping vertices_mapping;
-                vertices_mapping.reserve( solid_.nb_vertices() );
                 for( const auto vertex_id : Range{ solid_.nb_vertices() } )
                 {
                     vertices_mapping.map( vertex_id, vertex_id );
diff --git a/src/geode/model/mixin/core/vertex_identifier.cpp b/src/geode/model/mixin/core/vertex_identifier.cpp
index 152ca4282..a698b9e5d 100644
--- a/src/geode/model/mixin/core/vertex_identifier.cpp
+++ b/src/geode/model/mixin/core/vertex_identifier.cpp
@@ -78,6 +78,16 @@ namespace geode
         return component_id == other.component_id && vertex == other.vertex;
     }
 
+    bool ComponentMeshVertex::operator<(
+        const ComponentMeshVertex& other ) const
+    {
+        if( component_id != other.component_id )
+        {
+            return component_id < other.component_id;
+        }
+        return vertex < other.vertex;
+    }
+
     template < typename Archive >
     void ComponentMeshVertex::serialize( Archive& archive )
     {