SUMMARY https://wayland.freedesktop.org/libinput/doc/latest/pointer-acceleration.html#ptraccel-profile-custom According to wayland, the compositor has to handle creation of custom acceleration curves. Currently, this is impossible to achieve kwin_wayland. This forces me to use X11 and xinput.
It's not missing, it just hasn't been implemented yet. :) *** This bug has been marked as a duplicate of bug 464868 ***