Too many movable static instances

If they are actually instances, there would be no hit at all. So I assume you mean copies of the same mesh.

Even if you have thousands of instances on the screen, the GPU only has to make one draw call, and move them all ( at once ) is just like moving one mesh.

You can turn them into ‘real’ instances in the editor, but you end up with one kind of ‘big mesh’.

I’d suggest something like

because after instancing with that you can still move them independently.