Common sense tells me that I fail to see how full rom squats benefit anything but strength through the full ROM. For a powerlifter yes, but for a track athlete it’s unnecessary.
As far as number of motor units recruited, you can do this without even doing a squat and have the athlete stabilize a heavy load just off the squat rack and rerack it after stabilizing it.
Most of the time a very large portion of Hip/knee/ankle ROM is unsupported in track unlike in weightlifting were it’s always supported. Therefore I can achieve specific strength, better flexibility and more specific range motion and mobility in joints through Mach, dynamic flexibility, hurdle mobility, and sprinting/throwing/jumping. If you want great weightlifters then fine do full range of motion, but something my kids may do 2-3 days per week will on have ancillary and supplementary effects to begin with so you might as well work them in the weight room through ranges of motion that are supported for the activities they are participating in the first place.
I don’t buy a lot of the endocrine response garbage, the endocrine system responds to stress and full range vs 1/4 doesn’t squats doesn’t change the overall stress, the percentage of maximum weight that the ROM can handle is the stress. If I put 400lbs safely on a kids back and he does 1/4 squats, he is going recruit larger and more motor neurons to just stabilize the weight than if I put 135lbs on his back and he does a full squat. I am interested in the length-tension relationship of the muscle at certain ranges of motion, not the full range.
Post the EMGs showing that 1/4 squats give you the same gluteal and hamstring activation as deep squats because the info is against you right now.