I'm 99% sure this doesn't work if you're talking about the uppercut reset. Ex smoke bomb by-passes knock down invincibility, but it's still blockable. Kinda like Jax's ex ground pound: even if you try to tech roll or delay wake up, you will still get hit. Both attacks do not by-pass wake up attack invincibility however.
Why it's possible to get a guaranteed F4 ex smoke bomb reset, I dunno. But judging from how long he was on the ground, I'm gonna say the uppercut reset is blockable.
