I mapped mwheelup (mouse wheel up) and mwheeldown (mouse wheel down) to other things, and mapped zoom+ to keypad +, and zoom- to keypad -. It seems using keyboard keys gets registered too many times for zoom, causing it to radically zoom in/out, as opposed to using the mouse wheel where it feels more controlled.
Putting a zoom slider on the monolith would let me more accurately select a comfortable zoom level by moving the slider with a left mouse click instead of trying to find a perfect timing to get a comfortable zoom when using the keyboard.
Thanks!