More explicit zoom increment control

While you can zoom in smaller steps using CTRL+MMB-drag, it would be very nice (and a lot more intuitive) to be able to explicitly reset/adjust the amount the wheel zooms.

(What determines wheel-zoom increments? Grid size?)

I'm thinking a slider that allows the user to increase/decrease scroll wheel zoom increments, PLUS an "enable" checkbox for those times one would prefer blender to do whatever it's currently doing (ie, auto-setting the zoom increment).

IOW: a user-defined zoom control with an enable/disable switch.