Haha! Yeah, I’ve ridden through the area before (except Faindouran – FoA). 10km of dubious terrain vs. 90km of good terrain, I like those odds…
I have a lot of faith in the ability of the gravel bike to pick through tough terrain if you’re climbing or on the flat, I’ve been amazed at what is rideable (e.g. the worst bits of Glen Kinglas from Etive – Orchy, Gaick Pass, Loch Builg, Glen Tilt), in fact, I’m coming to believe that it’s only really at speed that you lose out to an MTB.
Descents – less so, but I don’t live for the descents on the gravel bike so am happy to keep speed in check and just roll down. I run 40mm Terrenos which have proven exceptionally reliable so far, and that’s running tubes (no punctures at all until Hawthorne season started). I’ll be running tubeless from now on which would allow slightly less pressure as well.
As you say though, go in with the eyes open and prepare for some hike-a-bike, is worth it for the good stuff.