Simple.
Don't use it.
Replace Back + 3 with a forward jump 2. I haven't ever dropped a Harley combo, under any circumstances, because of this decision alone.
Though note: Under laggy circumstances, the timing on your combo doesn't change, only the time at which the move is registered on screen changes. That's it.
The B3 almost feels like a cancel after TS1. It's strange, but you can be quite early on B3.