it could at that time send the command to activate the GPS unit and start its initialization.

That command is called "opening the serial port".

but I spent a lot of time last night staring at a map screen with no text, despite toggling the popup feature on and

It appears that the software can become confused and not realize you're coming up on a turn. It was estimating 230 miles to next waypoint on a 139 mile trip I made.

That way you could at least switch tracks and adjust the volume without exiting the GPS software.

You should get a remote for your empeg

I'll be selfish and say that autorouting is more interesting to me than practically any of your wishlist items.

Maybe I should take my laptop and try to work on some of this stuff for the hour I'll be on the train Friday morning.