I noticed the changlog mentioned some fixes for Linux, but it also states small fixes were implemented. Does this include small fixes and improvements for the Windows version as well ? Do I want to download this update if I'm running Windows ? Or is it safe to skip ?

I downloaded the update and the performance got worse, for some reason.

The frame rate ran smoothly before, now is borderline unplayable. And nothing else changed in my computer since the last time I played, so it has to be the update.

Try adding NOSMOOTHMOUSE to the end of the target line to revert to the earlier system.
Or other options in the included readme.txt
See PIC: