I like the idea. Some previous conversation I remember (2+ years ago at this point) kind of landed on "if the clothes don't hide it on your hip/back naturally, it's too big to conceal".
While I agree on that for big handguns like the .50, Heavy Revolver, and anything with elongating attachments, something like the Combat Pistol or SNS (maybe even just those two, considering their designations as "compact") should be concealable for the lower damage tradeoff. I'd even like this holster purchasable from the gun store for normally licensed folks too, as my character always feels like he's got a target on his back with criminals looking for a free gun.