If you dont wipe the FP takes around and hour. 45min if you skip the worthless bonus boss.
So? But you will wipe occasionally (and often in your first runs, as you should). Whats the problem to let you respawn right before the boss? Always running back huge distances is just a useless timesink, which is clearly nit required in this FP.
And the bonus boss being worthless, because of poor loot design for the FP is a major complaint.