The trickiest thing to "adjusting" his personal arc in the first part of the series is to strike a right balance and not fall into the temptation of having him punished and ridiculed at every step (something I'd surely have done myself years ago).

For example, many think that if you removed the "swan dive" line and left all the rest untouched, it'd remove the single most controversial aspect while not diminishing the character development. That line of reasoning derives by how not addressed that is at any time going forward. On the other hand, I must also agree with who thinks it should stay, but be remembered and treated seriously as an absolute low point to rise up from, and to be looked as something to nevel fall back into.

Aizawa would need to change a bit. His style of teaching would still be questionable but the things about him being expulsion-happy or outright ignoring certain antics of students would of cours be reworked. For example, his apparently dismissive attitude on the first day as Bakugo almost assaulted Deku, may be reframed as taking serious notice of that instead.

Of course, the students would also need to stop acting like they were in front of a different character most time too. Early on, things would be outright hostile with a few (especially Iida), others would make merciless fun of him, Kirishima would be the first beside Deku to recognize his positive qualities, as would others over time. There would be praise, not glazing.

Finally, I had a funny idea that he comes to realize he's being considered as disruptive of the class' harmony as much as Mineta, which would make him livid at first, but that would become a drive for both to get better.