Jab3-->Jab1 comes out 2 frames slower than shielding which happens a RIDICULOUSLY long time after Jab3 anyway. I highly, highly doubt that Jab3 true comboes into Jab1 on any character at any percent. MAYBE Bowser at like 100%+. For Jab3 to link to Jab1, Jab3 would have to add 13 frames of hitstun and no additional knockback, which I don't see happening.
Falcon's Jab doesn't work that way. He has weird IASA values on his Jab that I don't fully understand.
His Jab 3rd hit IASA normally links into Rapid Jabs, HOWEVER what I discovered a long time ago is that this IASA can also lead back into Jab 1 if you use certain inputs. By holding the A button, releasing after Jab3, and then timing the A button again at a certain point, Falcon cancels the lag of his Jab3 with Jab1.
Another weird thing is that pressing A twice to do two Jabs, delaying, and then holding the A button causes Falcon to do a Jab 3 that is IMMEDIATELY interrupted by Jab1.
Hence the Gentleman cancel, which I believe needs to be abused more by Falcons. But at any rate, I want some research done on the frames of this AT. At around 100%ish or so, I've done 50% combo strings in training mode on fastfallers to give you an idea how much stun Falcon's Jab3 does and its ability to loop back into Jab1.
And I seem to have heard some discussion about U-air out of shield. Trust me guys, it's really really good (especially against characters like Wario). Just nobody seems to understand except me, partly because I spent hours trying to perfect my useage of buffered U-air out of shield. And one of the neat things about buffered SH U-air is that it actually ends before you touch the ground, enabling you to do a midair jump or aerial specials immediately after.