Unbelievably beautiful route with great company. We left at 08:20am which was perfect as it was freezing in the morning but quite comfortable by that time (and all day). This route goes fairly high and is a bit of an adventure to just get to the start and finish (shout-out to our boy, Hector, who drove us as far up the ridiculous road towards Upis that he could). Logistically, this would be MUCH simpler to do starting from the main road at Tinki and doing a full loop of ~65km, but that would be an ass-kicker. Someone should do it though.
Otherwise, I recommend going the way we went (Upis -> Pacchanta) and camping as high up the road as you can. Get a 4x4 car with high clearance for this road. And then you get to finish at the hot springs in Pacchanta which are great. The road down from there is much easier.
The day itself though - fantastic. The route is mostly very easy to follow with a lot of open country and animal tracks to follow. The high passes kicked my ass a bit on this one and Joaquin showed he was much better acclimated than me today. We really squeezed the last seemingly endless descent to sneak under 6h00.
Note - we did this unsupported in that we carried everything and got stream water to refill bottles. There are basically 0 options to buy anything en route as of 2021, so bring everything you need.