diff --git a/forge/src/main/java/org/embeddedt/modernfix/forge/dynresources/ModelBakeEventHelper.java b/forge/src/main/java/org/embeddedt/modernfix/forge/dynresources/ModelBakeEventHelper.java
index c05dd603..0aeb9fac 100644
--- a/forge/src/main/java/org/embeddedt/modernfix/forge/dynresources/ModelBakeEventHelper.java
+++ b/forge/src/main/java/org/embeddedt/modernfix/forge/dynresources/ModelBakeEventHelper.java
@@ -21,6 +21,7 @@ import org.embeddedt.modernfix.util.ForwardingInclDefaultsMap;
 import org.jetbrains.annotations.Nullable;
 
 import java.util.*;
+import java.util.function.BiFunction;
 
 /**
  * Stores a list of all known default block/item models in the game, and provides a namespaced version
@@ -28,7 +29,11 @@ import java.util.*;
  */
 public class ModelBakeEventHelper {
     // TODO: make into config option
-    private static final Set<String> INCOMPATIBLE_MODS = ImmutableSet.of("industrialforegoing", "vampirism", "elevatorid");
+    private static final Set<String> INCOMPATIBLE_MODS = ImmutableSet.of(
+            "industrialforegoing",
+            "mekanism",
+            "vampirism",
+            "elevatorid");
     private final Map<ResourceLocation, BakedModel> modelRegistry;
     private final Set<ResourceLocation> topLevelModelLocations;
     private final MutableGraph<String> dependencyGraph;
@@ -79,7 +84,7 @@ public class ModelBakeEventHelper {
             private void logWarning() {
                 if(!WARNED_MOD_IDS.add(modId))
                     return;
-                ModernFix.LOGGER.warn("Mod '{}' is accessing Map#keySet/entrySet/values on the model registry map inside its event handler." +
+                ModernFix.LOGGER.warn("Mod '{}' is accessing Map#keySet/entrySet/values/replaceAll on the model registry map inside its event handler." +
                         " This probably won't work as expected with dynamic resources on. Prefer using Map#get/put and constructing ModelResourceLocations another way.", modId);
             }
 
@@ -100,6 +105,12 @@ public class ModelBakeEventHelper {
                 logWarning();
                 return super.values();
             }
+
+            @Override
+            public void replaceAll(BiFunction<? super ResourceLocation, ? super BakedModel, ? extends BakedModel> function) {
+                logWarning();
+                super.replaceAll(function);
+            }
         };
     }
 
@@ -139,6 +150,19 @@ public class ModelBakeEventHelper {
             public boolean containsKey(@Nullable Object key) {
                 return ourModelLocations.contains(key) || super.containsKey(key);
             }
+
+            @Override
+            public void replaceAll(BiFunction<? super ResourceLocation, ? super BakedModel, ? extends BakedModel> function) {
+                ModernFix.LOGGER.warn("Mod '{}' is calling replaceAll on the model registry. This requires temporarily loading every model for that mod, which is slow.", modId);
+                List<ResourceLocation> locations = new ArrayList<>(keySet());
+                for(ResourceLocation location : locations) {
+                    BakedModel existing = get(location);
+                    BakedModel replacement = function.apply(location, existing);
+                    if(replacement != existing) {
+                        put(location, replacement);
+                    }
+                }
+            }
         };
     }
 }
diff --git a/forge/src/main/java/org/embeddedt/modernfix/forge/mixin/perf/dynamic_resources/ForgeHooksClientMixin.java b/forge/src/main/java/org/embeddedt/modernfix/forge/mixin/perf/dynamic_resources/ForgeHooksClientMixin.java
index 655315d3..84652988 100644
--- a/forge/src/main/java/org/embeddedt/modernfix/forge/mixin/perf/dynamic_resources/ForgeHooksClientMixin.java
+++ b/forge/src/main/java/org/embeddedt/modernfix/forge/mixin/perf/dynamic_resources/ForgeHooksClientMixin.java
@@ -1,5 +1,6 @@
 package org.embeddedt.modernfix.forge.mixin.perf.dynamic_resources;
 
+import com.google.common.base.Stopwatch;
 import net.minecraft.client.resources.model.BakedModel;
 import net.minecraft.resources.ResourceLocation;
 import net.minecraftforge.client.ForgeHooksClient;
@@ -9,6 +10,7 @@ import net.minecraftforge.fml.ModContainer;
 import net.minecraftforge.fml.ModList;
 import net.minecraftforge.fml.ModLoader;
 import net.minecraftforge.fml.util.ObfuscationReflectionHelper;
+import org.embeddedt.modernfix.ModernFix;
 import org.embeddedt.modernfix.forge.dynresources.ModelBakeEventHelper;
 import org.spongepowered.asm.mixin.Mixin;
 import org.spongepowered.asm.mixin.injection.At;
@@ -16,6 +18,7 @@ import org.spongepowered.asm.mixin.injection.Redirect;
 
 import java.lang.reflect.Method;
 import java.util.Map;
+import java.util.concurrent.TimeUnit;
 
 @Mixin(ForgeHooksClient.class)
 public class ForgeHooksClientMixin {
@@ -32,11 +35,16 @@ public class ForgeHooksClientMixin {
         ModList.get().forEachModContainer((id, mc) -> {
             Map<ResourceLocation, BakedModel> newRegistry = helper.wrapRegistry(id);
             ModelBakeEvent postedEvent = new ModelBakeEvent(bakeEvent.getModelManager(), newRegistry, bakeEvent.getModelLoader());
+            Stopwatch timer = Stopwatch.createStarted();
             try {
                 acceptEv.invoke(mc, postedEvent);
             } catch(ReflectiveOperationException e) {
                 e.printStackTrace();
             }
+            timer.stop();
+            if(timer.elapsed(TimeUnit.SECONDS) >= 1) {
+                ModernFix.LOGGER.warn("Mod '{}' took {} in the model bake event", id, timer);
+            }
         });
     }
 }