I'm a little confused by the potential for accidents. If a customs officer is ultimately going to pull the firearm, the other person has to have done something. A CBSA officer pulling out the gun for no reason is an issue you'd have to deal with through legislation or disciplinary procedures or whatever.
I don't know what the expense would be to post it. I don't really see the need, personally. If it's affordable, then I guess it's a potential good step. I don't know. I think there would have to be some thought to that. It's tough for me to answer that off the top of my head.