I use CSS to collapse specific topics by topic ID. I find that's more fitting than collapsing topics by user id.

However, there are a couple of forum members that consistently create topics that are uninteresting to me. In that case, I simply style a pseudo element on the user id element, I think I use the ::before pseudo element. I absolutely position it so it fills the whole width of the topic listing and make it the same color as the background to it blots out the topic completely. That makes it look like a gap in the listing instead of collapsing, but it works compatibly with the other approach.

I have some doubts I can collapse a post within a thread, otherwise I think I would have done that already. However, It seems like it should be possible to blot it out in a similar way as I do in the topic listing. I imagine then I would simple have huge blotted areas that I'd have to scroll past. I haven't bothered because it hasn't really been necessary.

What I mean is that each post has a name next to it and it's from that I decide to not read the post. I simply scroll past the post when I see the name on the left reminds me I'll likely not be interested. Same thing I'd have to do if I had added CSS to blot it out, so there's really no point in blotting it out. I just scroll past it without reading it whenever I see a name next to it that is consistently uninteresting.

Admittedly if the post is too long (like this post I am writing…) then I'll probably use the minus sign feature to collapse it, and that causes the rest of the content to automatically move up into view. I'm probably fine with that because that's the same type of button on macos windows for minimizing them. I don't associate the buttons with ratings, and in fact I use CSS to hide all the "ratings" and stars.

So, yeah, I mostly just scroll past a post with certain names next to it without reading the post, no special software needed, no special effort. It does seem to take a bit of discipline.