I saw the QuickVent Safe and thought it makes sense to use with our xEMs. My partner and I both have an xEM but wish to be distinguished by our other access systems. This means we want to use the existing IDs on each xEM tag.
Does the QuickVent Safe allow you to program multiple existing tags to open it? Or do I need to clone the ID from the manufacturer shipped card to our xEMs?
Okay, so I just found it and am answering my own question here 
It should be possible to program additional cards (or xEM tags):
Basically you put a paperclip into a little hole to press down a button for 3-4 seconds holding the card against it. This then becomes a “master card” to program new cards (or your xEM).
So this is a nice one!
Just be aware that the safe seems to go to sleep after long periods of non-use… you have to kind of hit it to wake it up. I don’t know if that’s by design or if my batteries are just re-seating when I hit it haha 
Got mine and it works like a charm! Detection of the tag happens when you really hold it up close. This is fine/acceptable.