Ok, here's one vote in favor of what's called "add-a-gun". It's main purpose is CYA. In the event (God forbid) you ever end up in court. You are the defendant, and some POS attorney for the plaintiff is grilling you if you are HCP qualified for the handgun you shot the plaintiff with, you will be able to say "yes" and end that line of questioning.
I might be an overly cautious sort, but I want to lessen the opportunity for some dirt-bag ambulance chaser.
The range keeps record of your "added qualifier". You get a copy for your safe keeping. Nothing goes to the state on the "add-on" - not that I know of. Nothing regarding your weapon's serial number ever goes to the state, even on the initial qualifier. That got struck down a few months ago.
It's about $30 for a little more peace of mind. Maybe it's just a racket for the range. You decide.