LFB Yes.

But ideally you would be LFB on and off as you go through a series of corners. Say an s bend. So you can be maintaining engine revs (somewhere near your turbo having an effect) and at the same time slowing for the corner. then releasing the car before reapplying LFB.

If you did your braking the usual right foot way you would be constantly dropping off the boost power band, and would loose seconds (in a race) waiting to build revs again.

Thats why I say its only for track, its not really of any use on the road compared to HnT. Its a very situation specific, and given that on the road theres an element of un-predictability its easy to get your feet mixed up in a panic situation. In fact Ive had to LFB completely to a stop (and stall the engine) because there wasnt the space (before the fresh obstacle) and grab the clutch and reapply the brakes with my right foot. IYSWIM