Does everyone who plays this mod have 250 milliseconds of mouse lag at all times? I just reinstalled this after a 6 year hiatus, out of curiosity I checked my last doomsday (Doomsday Kickstart 2.09) from around 2009 or so and there's no mouselag. I do remember high particle counts causing occasional spikes of mouselag in 2.09, but generally it was normal. It's a real shame because this mod looks great apart from this huge problem. I tried disabling anti-aliasing and v-sync, to no avail. I'm surprised there's no other posts here noting this issue, is the solution so obvious I missed it somehow? I find it hard to believe everyone here is universally willing to accept 250ms of mouse lag at all times. If I can't fix it I will unfortunately have to ditch the mod.
Only other thing I can think of is I play with a gaming mouse and the high polling rate might be overwhelming what the executable can handle... I'm going to try this next. Doesn't make sense that 2.09 would be fine though.