I have the same issue with the big toe on my right foot. It doesn’t flex nearly as much as it should due to a lifetime of muscular imbalances. Stiffer shoes helped initially, but now it’s not as big a deal as my toe flexibility has improved quite a bit since starting the UA methods. I do have to be careful, though, as it can get still get sore from time to time from doing the SJSs.
A big benefit of the split jump squats is the eccentric loading. I would think that squat jumps and/or Bulgarian split squat jumps would produce the most similar training effects. The order that you have them listed seems like the appropriate ranking to me, but I’m far from an expert on this stuff.