diff --git a/MobileGL/MG_State/GLState/BufferState/BufferState.cpp b/MobileGL/MG_State/GLState/BufferState/BufferState.cpp
index 3be5c606..1b3fec1e 100644
--- a/MobileGL/MG_State/GLState/BufferState/BufferState.cpp
+++ b/MobileGL/MG_State/GLState/BufferState/BufferState.cpp
@@ -64,7 +64,9 @@ namespace MobileGL::MG_State::GLState {
                         }
                     }
                 }
-                m_bufferObjects.erase(it);
+                // Key-based erase skips FastSTL's successor-iterator scan, which is
+                // pure overhead here and dominates delete-heavy frames.
+                m_bufferObjects.erase(index);
             }
             m_indexGenerator.Delete(index);
         }
diff --git a/MobileGL/MG_State/GLState/Core.cpp b/MobileGL/MG_State/GLState/Core.cpp
index 086e615f..30a7851e 100644
--- a/MobileGL/MG_State/GLState/Core.cpp
+++ b/MobileGL/MG_State/GLState/Core.cpp
@@ -80,11 +80,16 @@ namespace MobileGL::MG_State {
 
         void GLContext::MarkBufferObjectForDeletion(Uint index) {
             if (ValidateBufferObject(index)) {
+                // GL semantics: deleting a buffer detaches it only from the CURRENT
+                // context's bindings, including the currently bound VAO's attachment
+                // points; attachments in other VAOs must survive (the shared_ptr keeps
+                // the data object alive, matching the spec's deferred deletion). The
+                // previous every-VAO scan was wrong per spec and O(VAOs) per delete —
+                // with one VAO per chunk section, vanilla's steady buffer churn made it
+                // dominate the render thread and FPS decay over session time.
                 auto bufferObject = m_bufferState.GetBufferObject(index);
-                auto& vaos = m_vertexArrayState.GetAllVertexArrays();
-                for (auto& vao : vaos) {
-                    if (vao == nullptr) continue;
-
+                const auto& vao = m_vertexArrayState.GetBoundVertexArray();
+                if (vao != nullptr) {
                     if (vao->GetIndexBufferBindingSlot().GetBoundObject() == bufferObject) {
                         vao->GetIndexBufferBindingSlot().Bind(nullptr);
                     }
diff --git a/MobileGL/MG_State/GLState/FramebufferState/FramebufferState.cpp b/MobileGL/MG_State/GLState/FramebufferState/FramebufferState.cpp
index 618dd157..e0177788 100644
--- a/MobileGL/MG_State/GLState/FramebufferState/FramebufferState.cpp
+++ b/MobileGL/MG_State/GLState/FramebufferState/FramebufferState.cpp
@@ -65,7 +65,7 @@ namespace MobileGL::MG_State::GLState {
                         bindingSlot.Bind(GetFramebufferObject(0));
                     }
                 }
-                m_framebufferObjects.erase(it);
+                m_framebufferObjects.erase(index);
             }
             m_indexGenerator.Delete(index);
         }
diff --git a/MobileGL/MG_State/GLState/RenderbufferState/RenderbufferState.cpp b/MobileGL/MG_State/GLState/RenderbufferState/RenderbufferState.cpp
index b2b30d9a..53de346b 100644
--- a/MobileGL/MG_State/GLState/RenderbufferState/RenderbufferState.cpp
+++ b/MobileGL/MG_State/GLState/RenderbufferState/RenderbufferState.cpp
@@ -57,7 +57,7 @@ namespace MobileGL::MG_State::GLState {
                         bindingSlot.Bind(nullptr);
                     }
                 }
-                m_renderbufferObjects.erase(it);
+                m_renderbufferObjects.erase(index);
             }
             m_indexGenerator.Delete(index);
         }
diff --git a/include/FastSTL b/include/FastSTL
index 644b3b01..34f55f9d 160000
--- a/include/FastSTL
+++ b/include/FastSTL
@@ -1 +1 @@
-Subproject commit 644b3b01e6e7dcb6a67818289d2fb9bbe85232f2
+Subproject commit 34f55f9df26be2c0d618252dd9c4ff6ec1741b23