With due respect I found your video a bit exaggerated about the terrain and required skillset.
It’s really not encouraging for the new travelers to explore these areas with such reviews. Even an average driver like me who started properly driving about 5 years ago, even got my license last year made it to Basho Valley with ease, that too in my 2wd 1998 Surf with family.
Yes, the drive is not for the faint of heart, the first suspension bridge gives you chills but it’s fun to experience it as unlike the road bumps this bridge sway is something totally different. Not a single point in whole way is narrow enough that makes you drive on the edge. Overtaking/passing through another vehicle is bit hectic but doable with patience. No extremely steep uphills/downhills. Took a wrong turn uphill (11:52 at your video) ended up at a dead end with few houses, then came all the way back to the right track.
Again, not criticizing you at all but consider it as constructive criticism if it suffice. As you claimed about your off-road experience, this vlog is sheer exaggeration about the terrain. This is not extreme off-roading and navigator is certainly not necessary.