I took both last year but always wore the open face. I very nearly regretted it. Had a big off after clipping a stump and landed face first. Somehow managed to walk away with just light grazes. It could easily have been worse. Someone else hit the same stump and definitely looked to have come off worse.
This year I’ll be taking both but unless it’s very slow and muddy will probably go with the FF. I’m old and don’t heal quick anymore.
I noticed in a video of one of the Italian races many racers use both. Open with the FF on the backpack for the transitions and FF with the open on the backpack for the stages.