I’ve done it on a hardtail loaded with camping kit and it was no bother….. just goes on ….and on…just a mindset thing.
Anyone attempting it on a road double (53/39) is bonkers, on drugs or has thunder thighs and excessive lung capacity.
I reckon I’d have to stand on the pedals for a lot of it on an ordinary road triple system.
When descending just remember how far away the nearest A & E Dept is!!!!! Personally I was glad to accept a slower ascent for the pay back of larger tyres and disc brakes on the way down. If I’d have been on a road bike I think I would have gotten cramp in my fingers from the braking effort. Yes, I am a coward when it comes to big descents on skinny rock hard tyres and twitchy skinny bikes.
If you are there it Has to be done though…I carried on up the LR track to the mast.
The best mtb tracks out of Applecross that I’ve tried are the longer one to Kenmore on Loch Torridon or the short track over to Sands.