imo it's not about BR, but about good lines. for example:
1.
the bridgeroll will give you a little advantage only, since you have to take a wider line in the left-hander.
But on a bad line in the first corner you will loose a lot more. (no airbrake, only a little steering+2 sideshifts on 1st and 3rd pad)
2.
If you can't do the good line, you can't make that BR (in most cases)

BTW: great story indeed :d