I had no idea 66A+B isn't safe. I never get punished for it. Perhaps it's safe on tip range due to pushback? Idk
aPat, Omega, Pyrrha, Siegfried, NM, Cervantes, Leixia, Aeon, Natsu, Xiba, Yoshimitsu. Those are the people that can punish it right off the top of my head. This list would be much different if after you landed it considered you grounded but it doesn't. 66A+B actually doesn't have much pushback at all, some people just don't like to punish it even though you can get a launcher. Lol
Edit: I also didn't know that 3A 22_88BB was a combo. I thought the only thing you could get from a 3A was a 3A+B
Sometimes it's hard to land. You also have to sidestep to whatever side they tumble to. It does like 71 damage though. I've gotten it to hit reliably on medium to larger characters. You're taking a risk with smaller ones due to their glitchy hitboxes.