SDNerd has occasionally ridden his 990 up and down short stair runs - NBD ... Supermotos - pfffffft ...
Shit - that looks pretty damn hazardous. Near-zero margin for error, and even though speeds aren't high, there is no get-off on that "circuit" that wouldn't involve some pain. Pretty certain I wouldn't be able to clear most of those log setups, and all the crap that lines the route one can get snagged on look far worse than any ruts I've inadvertently gotten myself into.
Not for me, but great to see people willing to take it on. Sadly, it'd never be allowed here in nanny-land.