I have been in that area a few times, and photographically I am not impressed. Its better from the train than for photos. I will still refer to the one near Rockwood as the Min-High Line, or whatever canyon we want to call it.
The postcard I remember that said The Mini-Highline, and Beaver Creek canyon, was a special excursion I think, with two engines, split apart by 3-4 cars for the upcoming High bridge on the regular High Line!!!
When I was there in 2014 I tried to get a spot below Shalona crossing, and walked toward the field between your shot and the crossing to do a broadside with some horses in the shot. Was only marginally successful. The train is always working hard in this whole region from Hermosa to Rockwood which makes it a good show.
Greg