You can do this yourself using ublock origin. (A browser addon).
A forumer made this trick a while ago.
Copy paste the codes below. Replace USERNAME text part with whichever poster's name you don't want to see. Make sure no spaces. Each set is its own line.
Open dashboard>myfilters>copypaste in Ublockorigin hit apply.
1. To block posts made by a specific user appearing:
runescape.com#?#article.forum-post:-abp-has(> div > h3 > a:-abp-contains(/^USERNAME
$/))
2. To block any threads made by a user
runescape.com#?#article.thread-plate:-abp-has(> a > div > p:-abp-contains(/^created.by.USERNAME$/))
3. You can properly hide hidden posts with
runescape.com##article.forum-post--hide-shunt
10-Jul-2021 22:14:31