That's the main reason I stick to "retro" style FPS games. Simpler movement systems simply feel better due to being far more consistent than anything with a ton of complex interactions.

Oh it's not the float math that's the issue. It's that ALL my old movement modifying behaviour worked on an assumption that the new slide physics thoroughly violate. Which is why teleporting/respawning/jumppads/razorwire/gravity are all breaking.

This would be so much easier if I had been tuning the movement with these physics in mind from the very start. I think this is just gonna have to be something I use in a future project because here it just breaks way too many existing systems(that already broke with the previous slide update).

oh it also broke jumppads....

FFS

and the fixes seems to be easier than I expected.
Just put the momentum slide at the start of the movement physics processing function

fixed the recoil problem. Still no WASD control.
This is evidently and order of operations + velocity mixing issue.
In order to get smooth slides I'm calculation velocity from past positions and need to somehow blend that with inputs.