Quote Originally Posted by Netflight
I figure Midoria turns full cowling off for the same reason we don't walk around with training weights on all the time. The constant strain could damage muscles, and be a detriment to his efforts to gradually increase what he can handle.
I don't buy that. This isn't constant resistance against himself, it's just constant strength. Also, neither All Might nor himself has demonstrated damage to himself at loads they could handle. 10% all day is fine from what i can see. He's stuffed up his body from impacts, not constant use of All For One.

Quote Originally Posted by Netflight
his quirk isn't "hard face",
LMFAO. That was good.

As for inconsistencies, I'm pretty pissed off at that as well, and now almost tired of being pissed off at it. At one point the story sounded very believable when Izuku mentions that Quirks have a basis in physiology with physical limitations. Sometimes though, we go back to them being magical powers.

When you think back to it, All For One actually would have had to keep lots of body strengthening quirks and such on hand to deal with the backlashes from other quirks he steals.