> The biggest benefit is that you can use drivers with actually correct acceleration curves

I just checked, and libinput does have the correct "flat" acceleration curve as an option, so I think we're good. ;-)

https://wayland.freedesktop.org/libinput/doc/latest/pointer-...

Being more serious, that document has a bunch of graphs of libinput's acceleration curves for different devices. I'd love to see a write-up of the curves you've implemented and why they're superior in your opinion.