Perhaps it is a result of growing up in Baltimore - but all I can think about in this thread is how easy it is to steal these very expensive items. The MaxTraxx pins and TSA locks would be like ripping a tag off a new shirt. Around here, if someone knows they're worth a couple bucks, they'll rip em off your truck in broad daylight while you're inside the gas station.
I'm super paranoid when it comes to securing items in and around my house and cars - because I've had my stuff stolen more times than I can count. If you're going to mount them externally, and leave them there, I'd come up with a better locking mechanism. I use Kanulocks for my paddleboards and other items I need to lock to the roof - a bit long and expensive for this, but something similar might be worth consideration.