The FBM has a manual sequential gearbox. That means the clutch isn't used and you have to ease of the throttle when shifting up (and, irl, blipping when shifting down)
The BF1 has a semi-automatic sequential gearbox wich means throttle cutting and shifting are done with paddles.
When shifting a H-shifter (unless it's a dogbox one) you allways need to use the clutch to change gear.
If anything in this post is incorrect correct me please!