We know about fitness, we know about dribbling. Since it didn't get much attention in the other thread I open this one because this deserves audience too. This proof is the one from eastside from german forums which I call the penalty proof (introducing fancy names here @CFCsjmishra ).
He simply tested with NIF and iHero Kaka penalties in the first minutes of a game. Turns out that NIF Kaka gets a boosted (=more green) penalty bar on 10chem and not on lowchem. No change of the bar on iHero Kaka regardless of chem.
Another advantage of this proof is that is applyable to older FIFAs since no touch dribbling isn't existent there. He did the test on FIFA15 (fitness behaves like in 16) and penalties get affected like in 16. Most likely this has been in every UT.