I could be wrong here but in a fg formation the holder is standing far enough back that the snapper cant just use one hand to snap it to him and have a snap thats low and hard. In order to do such a hard/low snap the long snapper needs both hands on the ball which physically causes him to go lower than a regular snap. If he were to only use one hand and stand further up the snap would be slow and probably high creating a giant cluster F.
I hope I explained myself clearly bc im a little confused as to what change youre trying to propose.