Yes. Sometimes I even update my thinking. Never try to leave a commenter hanging out to dry, though, so if I am quoted, or if anything I say is in response to a comment, or I make changes that I think might be relevant to a comment, I always actively call them out as edits.
As for grammar and spelling, Mrs. Mayo from Honors Freshman English would not be pleased if I didn’t have subject-verb agreement, though I have decided I will not be afraid to boldly split infinitives or leave prepositions at the ends of sentences for anyone I’m talking to. This isn’t Latin.