Thanks for making this page, it was very helpful!
Just wanted to add a few things. I was able to find the trail into the upper basin on the way up. It's a sharp left then turns back south right after the trail starts north along that grassy bench after the switchbacks up. You hit that bench going north and the junction should be within a few hundred yards. If you look left at the slopes coming north from the waterfall you can see it cutting SSW and diagonally to gain the upper basin. I found that it disappears shortly after gaining the upper basin, after traversing a bit through a narrow meadow and some woods. The rest of the route through the upper basin is basic and you have it down pat in the route description.
I actually took your ascent route down partially on purpose since I was waiting for some clouds to clear on the Gros Ventres and open up those views. It's not a bad option if you want a more scenic detour both of the Gros Ventres, Clause Peak, and some good perspectives of Hoback itself, and I think it really adds only between 100-200 feet of gain. I followed the spine of the northeast ridge on the way down and along this little plateau you see in your picture (535950). You can curl along the crest of it as it eventually curls south, then descend open slopes back down to where the trail fades at the beginning of the upper basin. Not a bad alternative.
I must have missed this comment back in August! Last night, I came across it after noticing you posting pics to the main page. It made me look at my pages, and there was the comment. Anyway, I plan to work your notes in when I get the chance.