I haven't thought this thru, so just throwing it out for brain-storming purposes.
I have AutoTaxi+ enabled, and I like the way that iFly initializes to the Taxi view for taxiing.
Nevertheless, sometimes, before I start to taxi, I'll go back to the Map to look at weather or terrain or something as I think about departure. But when it's time to taxi, there's no easy way to get back to the Airport Diagram.
So how about this: When you're in Ground mode, and when own ship is centered (so that there's no green dot button), the green dot changes to an Expand icon. (4 arrows on diagonals pointing outward.) That way, you could tap on that button and get back into the Taxi mode without having to click the zoom + button a million times.
Either that or make the zoom buttons adaptive in the sense that, if you tap and hold, or tap the + button three times quickly, it jumps into Taxi mode?
(It seems like a similar clever adaptive button could be used in Flight Mode, where, when you've tapped the Green center button, it changes to another button (like, view Destination? Or NRST? Or ?) until you pan away from ownship.)