I reduced the mouse sensitivity in-game to about 40, and it works in the workshop, but once I enter a level it seems to reset to 100. The slider remains at 40, but it feels like it is back at 100. I can still move the slider up and down, but no matter how low I set it, it seems like it effectively won't go below 100, although if I set it over 100, even to the maximum, then it does feels like whatever it set it to.