> Disabling acceleration is a big feature here, again something that makes sense on a trackpad but does not on a scroll wheel.

Ah, but it makes sense on Apple scroll wheels! I think that's why they never added a built-in option to disable it.

Nowadays the Magic Mouse doesn't even have a physical scroll wheel, but even on the Mighty Mouse, the scroll wheel was a little ball that could roll in any direction and didn't have notches, so acceleration made sense.

Acceleration + notches are what do not go together.