That pretty much defeats the purpose of the murder briefcase. I don't believe you hold the briefcase gun in the same manner which you use a regular gun, thus the personalized grip... you make my brain hurt. Next, when you put gas vents on you start exceeding the bounds of the briefcase which is supposed to be hiding the gun. The moment the gun isn't hidden, just go for an overt gun.
I don't think gas vents increase the barrel length like they did in older editions. They're just modification to the existing barrel. After all, they're decently hard to put on and until
Arsenal impossible to take off. Now it'll be super obvious you have a briefcase gun when you fire it, but that was already the case.
