Eh, depends what you mean by springing off his jab setup.
Like jab > up-B isn't a true combo. In fact, you can only barely powershield it if you hold shield and don't DI upwards - so I wouldn't gamble on trying to spring (I think we still have that startup time, though Sonic might be displaced enough to avoid a sweetspot up-B... maybe). Also, reading around, I just found out that apparently (?) moves have higher knockback (20% more?) if your opponent is in midair, so if that's true, you definitely don't wanna DI/SDI upwards on his jab.
I still have this sort of scar/memory from when I did a SH F-air on BL's shield thinking I was safe, then got hit by a sudden pivot F-smash while I was still in midair. I still don't know if that was because I was just not expecting it or if I was in legit ending lag ;_;
...And jab > up-B's.
Also, definitely remember my U-air getting beat out by his N-air. Umby saw it too -_-'
I need like, safe moves to use. Reading back, they said something about F-tilt, but isn't that laggy? or do you use that vs his aerials?