> About a year ago, all three big AI vendors could end up with strange "corrections" that would throw you off, but not anymore.

Without a history of diffs created by this method, I don't believe you.

> I am decent with English grammar so most of what needs fixing is typos I didn't spot or misplaced commas and periods inside/outside of quotes (I always screw that up without thinking—even though I know the rules! LOL).

The rules there vary by style guide and are not objective.

LLMs seem like massive overkill for something the red and green squiggles can already accomplish.