Tangentially related, I've been dropping Google apps for FOSS and especially FDroid alternatives. It seems wasteful for each app to be duplicating OSM tiles all the time. For things like Meshtastic as an "off grid" app, you'd want maps to be available with no data connection as well.

I'm not sure how useful it would be but pointing all of these apps to something like OSMAnd~'s downloaded maps makes a lot of sense to me.

That'll probably be the case regardless of where you get it from then, unless there is another variant or fork that uses something different like OSM or whatever.