If you mean the safe jump setup, the timing for his safe jump is fairly tricky to get down. It's probably the about the same difficulty doing raw 2c as 3b 2c, so I think it's fine to omit 3b.
To get the safe you jump you have to do:
combo > orbiter+explode > (dash 3b) > 2c > jump cancel > small delay* air assault > meaty air normal (J6C is most active aside from JA, so I use that).
From what I've noticed, the small delay* on air assault is the trickiest part, as it varies based on how extended your combo is. It's really easy to do it too soon and have your meaty whiff (giving you a fake high into low 2a), or doing it too late and it not being a safejump.
If anyone has any other way to do the safejump more reliably I'd be happy to hear as well, but this is what I've seen done in match videos.
As for dash 3b 2c input, you can hold [3] once your dash starts and you will still be dashing until you press B. This is one of the things I still can't do perfectly either though. I have less problems doing delayed rekkas and all the other stuff.