I have one of those and it's kind of a PITA. I actually didn't realize it blocked RF until after I bought it. It's annoying because I can't just tap my wallet on the MUNI gates or the card reader at work, I have to open up the damn thing and press the edge of the card poking out of the card holder against it and hope it works (sometimes it does, sometimes I have to pull out the card).

I probably just have too much junk in my wallet, but I can't ever just tap the wallet against an NFC reader anyway. It either doesn't read anything or it reads one of the other low-power NFC cards contained (I think I have 3-4). For quick access to a single card maybe you can get a lanyard or one of those retracty thingies people wear around their belt loops?

Well, if I was doing security at your company, I'd probably want employee credentials to be visible at all times, which would also happen to take care of your problem.

Employee credentials should not be visible when the employee isn't inside a secured area. If you work at a site with a Security Officer, try inviting them out to lunch and not hiding your credentials. See if they care.