it would be super cool to be able to import a jpeg image and the scale it up to match the way the grid snaps, and apply it as an unselectable background. If storing the image file serverside is too costly, you could always just do hotlinking of a hosted image.
I’ve done some design and technical experimentation work towards this already. It’ll land on Shmeppy before too long hopefully. It’s gonna be a few months of work to do I think (not cause it’s “hard” per se, just cause there’s a lot to do). Check out Uploading a map for previous discussions on this.