How about making the MSL & AGL instruments double as altitude buttons (uses no extra real estate) that pop up a field and large keypad with 1-9, 0, 00, 000, "cancel" & "accept."
You enter an assigned or intended altitude, press accept or cancel. The keypad and field disappear. When you get within say 300' of the altitude a large warning appears. Touching the screen anywhere removes the warning and resets to null awaiting next use.
(Use 5 & 00 for our esteemed VFR pilots. We all often are. Nothing wrong with VFR!)
Reduces altitude busting...