Prompted by another thread, I'd considered this trend before.
With many enduro series/races insisting on the wearing of full-face lids, many riders have taken to carrying an open face on their backpack for the climbs/transition stages.
*Photo borrowed from this site*
I can't help thinking you're far more likely to sustain injuries with a portable boulder strapped to your back than you are to injure your face.
A few years back at Gethin, I crashed in the rock garden with a full face and goggles and STILL managed to get knocked out and smack my cheekbone with a rock, making a large graze and bump, so you can still get things past a chinguard anyway..
It's a difficult one for race organisers to legislate for as some tracks are pretty full-on, places where I'd definitely like to be in a full-face but if it means carrying two helmets, I think I'd rather opt for open face, paired with some goggles for a degree of extra protection.
What does the panel think? Should full-face be obligatory?