I kind of agree with this. As we already know, the mere air pressure of 20% Deku is powerful enough to heavily injure Overhaul's arm, whose durability is around 4 tons scaling from the current 8% Deku (I will explain this later), while a direct hit at 20% is able to one-shot Overhaul according to Deku's words. So, at the very least, the blow itself is a few times stronger than the air pressure, which would make 20% Deku 8-B by default, as his tornado feat was already very close to 8-B.
Now the problem comes with Full Cowl 100%. The reason that I don't want to put a "likely higher" mention is because Deku and Bakugou's feat is very close to baseline High 7-A, which means that even if the blow itself was 2x times stronger than the air pressure, they would be still High 7-A. I do agree adding a mention that they did this with a shockwave.
As for All Might, since his feat is practically double to that of Deku and Bakugou, him having a "likely higher" mention or even + in his tier is not really out of question, but I will leave that for other members to decide.
As for the explanation I said earlier "Why Overhaul should scale from a Deku that was enhanced by Katsuma's Quirk?". The reason is simple, the improvement wasn't big at all, Deku was able to take hits and defeat
someone who was able to damage his Air Force Gloves, which even after Deku was "enhanced", they could still withstand his blows.
And before anyone says they could have been upgraded, first, there's no evidence of that, and second, Deku literally broke the gloves the same day Hatsume finished making them, which means she didn't have time to make an upgrade, just repair them.
