No I only use the box on DE lower body day for dynamic dorsiflexion.
Seriously Dan, I think that 12-15 reps has generally been the been the best rep range for rehabbing my shoulder. Higher reps may work too, but lower than 12 just never felt right to me, and if you have a rotator cuff injury than how it feels should be a good indicator (if it hurts it is too much).
Right now my shoulder feels like it is back to about 90% and I do a set of 10 every now and then but it just doesn't feel as good as staying over 12. But that is just me and I don't know your situation.