Just filter the unwanted user out of the posts you see. The app I use for Lemmy includes this feature. I use it to clean up my feed from gallowboob-type ubiquitous posters, as well as any headline that includes the words “slam,” “slams,” or “slammed.” I can also eliminate any headline ending in a question mark, as the answer is an automatic “no,” so the question is not worthy of my attention.