I have a lot of shoulder issues that are worsened by sleeping on my side or stomach. I also have a flat spot on the side of my face from always sleeping on it, and it gets worse the older I get. I'd like to be able to use overnight skin treatments without it getting all over my pillow.

Fair enough. For what it’s worth, I fixed shoulder problems with a combination of mattress, pillow and arm position thought the latter is less important.

I don’t have a flat face (yet?) though I can see how that could be annoying.

Wonder if making some kind of custom shaped bed (ie from memory foam) might be a useful solution?