Depends on what you mean by 'improve your post quality', if you use AI to generate whole/additional content for your post, than I don't think that's acceptable, AI generate the content by crawling in the internet and that might lead to Plagiarism. But if what you mean by improve your post quality is helping you with grammar and choice of word, and the whole content is based on your own thought, then it's acceptable, or at least you wouldn't do any plagiarism. However, even with not so perfect grammar and choice of word, as long as your post is understandable the reader won't mind.