Thats not a bad habit, especially if you're hitting it consistently. You're just not converting it right. Because F412 leans reptile forward, you can't NJP, but you can Back Jump punch. The combo I end up doing is F412xxFFB, Back Jump Punch (1), 21, F412xxSlide. I believe you can also hit the D3xxBF4 again at the end like the majority of reptile combos, but I never try for it online, too hard of execution.
With that said, I didn't know about the 1 bar uppercut 40%, so I'll be stealing that too lol.