A Gaited Saddle has built in Flair in the very front edge of the bar to keep the tree from digging and or freeing up shoulder movement, I do not see he has huge protruding shoulders, so that would not help
Some Gaited Saddles have extra high gullet clearance, but are normally only in the TWH Saddle and they would be way, way too wide.
A Fork Trees generally have about a 1" higher gullet clearance than traditional Trail Tree, but very few come in Semi-QH widths.
Have you tried a Semi-Qh with a cutback wither pad?
May all your Trails be happy and safe ones