As a retired LEO, I say that requiring documents like registration, medical, and pilot certificates to be personally carried is a relic from the last century and should be repealed. It literally takes seconds for the FAA guy to check your certificate status. Much as I was able to check vehicle registration and driver’s license status. And even not having DL in possession was not much of a problem, as we could have the DMV photo in no more than a few minutes, and that was eight years ago. I’m sure it’s quicker now.