Usmash is pretty easy to DI. That combined with its long animation makes it pretty punishable.
I've been thinking about the uses of grounded up b, the biggest thing holding it back is its horizontal range, but it is also pretty punishable by a simple airdodge, unlike usmash in most cases. It's frame 6 though not frame 1 according to our resource center.
Also
We definitely have the nB out of the trip, the only part where I am iffy on it being legit is when we stun and have to grab the nanner out of the air and JCT, if they can get out at any point it would be there.
It seemed like if I delayed the nB a fraction of a second, it made the nanner grab to JCT more flawless. We know we have atleast 3 frames to delay since dsmash is 20 and nB is 17, and the projectile travel time is pretty much negligible because the JCT puts you so close to them.
Like I said, if anyone can debug, this is absolutely worth it to test. It seems slightly easier than dashlocks, atleast when I was first trying to do them, but it would be an awesome combo and setup, regardless of %.