That's a thing?
Anyways, it's not exactly the same thing though. it's requiring you to add in an extra input, which you may as well just charge smash attacks the usual way.
Yup, it's my preference for charged smashes.
I'd disagree; from the sounds of it, an S4 player would probably build up muscle memory for always inputting C-stick
before deciding whether or not to charge it. Since not many are aware that C-stick + Z can be used to charge smashes in Melee/PM, they assume that once they hit the C-stick (their go-to muscle memory input - starting with their right thumb on A would probably feel as awkward as switching between X/Y or L/R), they've already committed to an uncharged smash attack.
I'd imagine that the bigger issue here is more mental than physical - confusion/hesitation over the thumb positioning and the order of button inputs, as opposed to the number of inputs involved, especially in this case.
While I could see how this would be an issue if it involved a second input with your left hand (L instead of Z) or a second input with the same finger in quick succession (C-stick input, then rushed to press+hold A or something), your pointer finger is usually already positioned over R or Z, so it doesn't take as much additional attention to get used to for covering the extra input.