The entire progression did not make any sense. Even assuming they showed everything, which is highly doubtful, Oda never showed them against significant opponents.
If Hell´s Memories is Sanji´s main power-up over the TS, why not show it against Vergo, or in WCI? Instead he has been spamming either base or DJ kicks. And then something which was also presented as huge power-up for Sanji, geppou/Sky Walk and connected Blue Walk, was shit on in WCI nonchalantly. One can argue HM is Sanji´s equivalent of G4, and he used it one time against fodder Wadatsumi.
If Oda argued that Sanji´s strength was not enough, he should have shown HM failing against a significant opponent, like let´s say he did in Water 7/Enies Lobby, where the Strawhats needed powerups against their opponents.
Zoro is not such a significant case like Sanji, because getting a new sword is by far not on the same level as getting a suit that increases every stat, and also gives you invisibility, especially if we assume that invisibility actually helps/evades CoO.
So yeah, i think Sanji showed everything, but why he has not shown it more often does not make sense.
And Zoro i do not think he has shown everything (Asura was a big powerup pre-TS, and Zoro showed improvement in every major attack compared to post-TS, the same will apply to Asura) but it will not be the uber powerful thing Zoro fans try to make it out to be.