Question: can I remove/replace old keys from the EWS memory LIMIT?

[workingonit]

OK, I'm cheap. I never bought a new "diamond" key from a dealer, as I didn't want to spend so much at a time on it, so I renewed the battery in my single original key (self-repaired), and bought a couple of aftermarket, uncut, remote-only (not to be used for anything but remote functions) for under $20.

Even though my wife lost one of them (note: I've never lost a key in my life), I carry the remaining one with me (in case the remote on my genuine key fails), so I don't have to open the X5 manually (saves wear & tear on the mechanism). It's been 2+ years since I got the remote-only keys, and I need to get some more, in case the already installed battery dies (and I can't install another).

Question: can I remove unused/missing keys from the 10? slots on the EWS key list? It's almost full (as I remember it, from the time I found it on my last Foxwell testing session, a few months back). I think there may be a slot or two left, but ???

Since the aftermarket key(s) came to me with a battery already installed (and sealed inside), I have no idea how long it will last (don't know the quality or age of the battery), and if I were to cut it open to replace it, I might screw it up (nearly did so on my original key, but at least I know that the rechargeable battery I installed should last many years...the original battery lasted nearly 20 years).

I store my most-used automotive tools in the trunk of the X5, so I'm always in & out, and I use the remote-only spare key a lot, so I want to renew/replace it before it dies.