Supercropping is a growers technique and does not necessarrily mean more yeild but is a means to control the growth of your plants. I do it during stretch to control the stretch.
My small plants get topped and LST'd from small babies, then Scrogged for flowering and supercropped for stretch. Lollypopped after seeing which branches will not make it to the top of canopy.
A more even canopy can mean a bigger yeild, so to some degree yes supercropping can increase yeild but only as part of it's contribution to a more ideal environment that you have created as a grower. ie it wont make up for poor growing, only compliment a good grow. Scroggsy.