it is done

core/src/mindustry/world/CachedTile.java

@@ -0,0 +1,45 @@
+package mindustry.world;
+
+import mindustry.entities.type.TileEntity;
+import mindustry.game.Team;
+import mindustry.world.modules.*;
+
+/**
+ * A tile which does not trigger change events and whose entity types are cached.
+ * Prevents garbage when loading previews.
+ */
+public class CachedTile extends Tile{
+
+    public CachedTile(){
+        super(0, 0);
+    }
+
+    @Override
+    public Team getTeam(){
+        return Team.all[getTeamID()];
+    }
+
+    @Override
+    protected void preChanged(){
+        //this basically overrides the old tile code and doesn't remove from proximity
+        team = 0;
+    }
+
+    @Override
+    protected void changed(){
+        entity = null;
+
+        Block block = block();
+
+        if(block.hasEntity()){
+            TileEntity n = block.newEntity();
+            n.cons = new ConsumeModule(entity);
+            n.tile = this;
+            n.block = block;
+            if(block.hasItems) n.items = new ItemModule();
+            if(block.hasLiquids) n.liquids = new LiquidModule();
+            if(block.hasPower) n.power = new PowerModule();
+            entity = n;
+        }
+    }
+}