I highly recommend you install the Copyleaks/Origin browser extension and just scan your post before posting if you doubt that the third-party grammar assistant might have changed your post too much. I consider it my responsibility, too, as when you are fighting against the unethical use of AI, you must scrutinize yourself in the first place. It is the same as submitting your research paper/article to any reputable platform as your own, you are required to scan it for plagiarism/AI detection before final submission.