Interesting. Maybe we can start to develop it to see how it goes.
Discussion
Yes, for sure. If you don't get to it first, I might take a stab at it myself in a couple of weeks. I'm not much of a mobile developer, but hopefully, my "backend" Kotlin skills can at least get it to a first draft.
I would be willing to try it regardless of battery consumption, if you give it a whirl. I'm using a personal relay from relay.tools exclusively for everything and get no notifications at all.