Taunt (1+3+4) is one of Bryan's most powerful and hardest techniques to learn in the game. It's a pose with a slow, but unblockable, mid hit with the knee which leaves Bryan at +16 frames on hit. Mostly used as a okizeme tool and at the corner.
How to Cancel
Bryan can cancel the Taunt in any direction or button, but because he also can cancel his startup, it can't be bufferable, so making the cancels to be exactly when his knee hits to guarantee the combo, and with the inputs being always clean and together when required, like f+2,1,4 being executed like f#2,1,4.
While the +16 allows for many things, the window is pretty much short to execute many of his moves and others being executed like a Just Frame, with a tight 1-f window. It's from this situation that Taunt Jet Upper(TJU) comes up. Probably the hardest(but viable) thing to do with Bryan. You first need to press forward at the frame the knee hits, then leave the input to neutral for 1 frame, then pressing back+2 at the same time in the next frame.
The command screen should be reading as:
While the Taunt itself is slow (i28), it's mostly used in the okizeme and the corner, since the opponent is more susceptible to be hitted by the taunt when they get up and in the corner their movement and wake up options are more limited. For example, after a Wallsplat you finish the combo with "b+3~f d/b+1+2", to recover earlier and guarantee the okizeme with taunt and try "Taunt f+2,1,4" for another knockdown or "Taunt B+4 f,b+2"(more harder) to launch them when they get up.