I decided that I really wanted to know what would break the 2147B loop, so I did some research in the only game I could get 60 fps footage from, BB:CS1.
Now, I really don't know exactly how Hazama's 5C, 2C och 2147B have changed since then except for the normals getting lower hitboxes, but the basic theory behind this should still be valid.
Turns out that there's four ways to drop it in CS1, namely:
1. Doing 2C too early or too late. There's 3 frames in total that will work, one more and the 5C can't be canceled anymore, one less and they're too low. I've got pictures showing exact heights for these three frames + if you do it one frame too early.
2. Jump canceling 2C too late. Again, there's 3 frames here you can JC at and still keep the combo going, the first possible frame, and the two after it.
3. 214B not coming out on the first frame possible in the air.
4. 5C not hitting on the first possible frame.
Nr 4 means that something must have been changed since then unless I've misunderstood something about advanced input for step type characters. In CS1 it appears impossible to do a dashing 5C, since you cannot afford even one frame of dashing animation come out. Please feel free to inform me of exactly what has changed, or of how I've misunderstood advanced input dashing normals for Hazama.
Nevertheless, this most likely highlights the difficuly level of the loop: one 3f real link, must JC early and do an early TK, and one 5f advanced input link at the end. Not that hard if you know what actually matters in it. I had no idea that the JC had to be immediate, and hopefully someone else than me learned something from this too ^^ Pictures may be editable to a format that is actually viewable if people ask for it
PS, For those saying that a 2147B input will give you a superjump, what are you guys doing? You won't since YOU'RE ALREADY HOLDING 2 FROM THE 2C. Mind you, a forward jump is still better since you get one frame of forward/backward motion in the air before the TK comes out, but accidental superjumps are not the real reason to use 963214B or 2149B