Overdraws are not a problem … the render geometry is pretty simple (sprites) and there is not alpha blending at all -all materials are unlit and masked opaque, only 1 texture sample-.
Problem is in “Game thread” and disappears when I turn off collisions so no rendering issues -my scenes are pretty simple-.
It would be interesting knowing how the “broad phase” of collisions is configured and knowing if it can be tuned someway