Any support like libinput under wayland?

I have a Kensington Expert Wireless Trackball Mouse, it is very close to impossible to use if I can't configure one of the (4) buttons to implement drag lock. I was just trying wayland on 20.04 and there does not appear to be any way to map buttons and enable one of the buttons as a drag lock button. Am I missing something, or has this been utterly ignored for all the years wayland has been in development? I'd be happy to buy some trackballs for wayland developers if it will increase their motivation to get this working :-).