I think it depends on the security baggage who care on the luggage bag, You also might check the rules for transporting like prohibited things such as (knives, pills, batteries, etc.) as you follow the rules and regulations there is no problem with it...

How hard would it be to get the gate check tags from the GA and then rip them off in the jetway - continuing onward to the overhead bins?

Since when does security/TSA care how many bags you have?

I see this happen many times - let the GA provide you with the gate check tag, but continue on into the cabin and hope the FA doesn't notice or care. If she does care, no harm no foul, you just gate check.

Obviously, I didn't see the guy at security or when he boarded. All of the bags were tied together. That's why he stopped in the middle of the aisle for several minutes, he was undoing his bags while people waited behind him.

He clearly was not an airline employee and he was travelling alone.

For years, I worked for an airline - including the years when some of the airports had the 'templets' at security.

I was working near security one day when 2 passengers from an international flight were flying domestic. One of them asked me if I could lift the templet - his carry-on bag was a tad big. I told him I would have to check it, and went to lift the bag, but it barely budged. Turns out it weighed just over 100 pounds. He said it was a piece of machinery (a gage or meter or something like that). I have no idea how he had traveled with it (it was a TPAC flight) and where he was planning on storing it on this domestic. We did not take any bags over 99 pounds. I ended up calling a ramp supervisor to deal with these guys.