I think "there is only one person working full-time on maintaining Linux input libraries and he's overworked" is probably a decent excuse. I don't know what you plan to do, but I would advise against forking unless you can hire a team to accumulate testing hardware and work on this for multiple years. What we have seen too often is these forks just fizzle and get forgotten, especially if they are only focused on getting one feature to work on one very specific device.
I’ve heard of tons of these patches people write for libinput, yet they are never in master. There’s nothing in the libinput README or FAQ about how they’re looking for help, and there are quite a few different authors. How is anyone supposed to know help is needed?
well i put it out there, but it was (apparently) very personal. I use zowie mice at 800 dpi and setting gui settings to 0.1 sensitivity (or 1 etc,c whatever is lowest) would result in several desktops worth of movement per mousepad (22 inches), really bad over all. i just wanted a single left-right corresponding with monitor edges which was never a problem across any os until recently which oddly started treating low dpi at 1000 hz really weird
i still got the patches somewhere and will post them soon. it basically let you set mouse speed scaling on a larger scale