I wouldn't worry about wasting the blood I already have, most of it is synthetic garbage. I haven't had a regular donor in...a very long time.

As for compatibility, I couldn't really say without trying. I've encountered more blood I could digest than what I couldn't. I would think you'd have as good a chance as humans did, before I'd ever tried them.

Either way, it's nothing I'd want to entertain if you aren't comfortable with the prospect.