I think you may be onto something interesting with this mechanic, all it needs is a whole bunch of polish.
During my playthrough, I wasn't attacked once. If I'm not taking damage, then all healing tiles do is annoy me for taking up inventory space. Also, I wish the return tile was less random. Having it be random means I just sit there desperately hoping it deigns to return an attack tile so I can progress the combat. Perhaps instead make it so it returns all tiles it attaches to, and then give it some openings or connectors to allow it to attach to things
I really think this could be cool if you polish it. I hope I get to see where this goes!