Thanks for taking the time to test! I'll see if I can figure something out for the next patch.
Hello, i found out that if i enable "Fast Dice" in the options i don't see the slowdown anymore in windowed mode.
That's ... not what that button is supposed to do :). I'll investigate.
Maybe that "Fast Dice" by cutting down the dice jumping and bouncing is somehow lowering the heavy load of whatever is causing the slowdown ?
If the slowdown occurs specifically while the dice are in motion that could very well be the case. In any case, I'm working on some performance improvements (including a vsync toggle) for the next patch!