just found another thread where someone created the backpack
Yup, that's mine.
I have not had a problem with the TSA. I was delayed briefly by local port security while boarding a cruise ship at one point, while they got a supervisor. They did not understand what it was. After 5 minutes of fiddling around they let me through.
The advantage of that setup is that you can utilize the straps and the backplate to make a pretty good backpack. It's OK as a carry on but where it really shines is in those situations where you have to hand-carry your gear a long way and/or use public transportation, as is the case when traveling via cruise ship and trying to dive in your own gear.
Otherwise, for air travel, I just fold up the straps, take off the wing and fold it up, and put the backplate in the bottom of my carry-on.
Either way, I can fit everything for a dive except tanks, weights, and fins. I like really large fins that are themselves over the size limit for a carry on, so I just check them. If my checked bag gets lost, I can buy or rent fins locally, and nobody steals them.
If I used smaller fins I could probably fit them in my carry on. In some situations it would be a worthwhile tradeoff.