Yes, Gary is correct. I think I've figured out a neat and elegant way for this all to work.
Basically, you watch the screen for a touch event, and if so, you buffer the speed pulses, and begin allowing them out, but at a throttled rate. Then after a certain timeout, the throttling is removed. So anytime you touch the screen, the lockout is temporarily removed, the touch is processed, and you have a few seconds to continue selecting things. Meanwhile, the position might accumulate some error, but at least the system will still indicate progress and update via GPS. And if your average speed is still pretty low, such as driving in the city with stop/go traffic, the system will "catch up" even if you continue to touch the screen, and if you are driving fast, while continuing to touch, the error will eventually be corrected by GPS.
Of course, this same system automatically presses "ok" for you upon startup.
Gary, it looks like they will update the position once the error is over a certain threshold.
Yes, I can make the nag go away via the Nav CAN bus, but that effectively denies the agreement. This new method Ok's it.
-Phil