I’ve seen some requests for such a feature (ignore list). While it is possible to add it, I am not going to do so now. When version 2 of SMF is released, ignore lists come standard. So you will have to wait until the forum software is updated. I don’t know when that will be, but it is in the foreseeable future, so be patient
My personal opinion is that ignore lists won’t solve any problems anyway. Discussions start to make less sense as members not on your ignore list still reply to drivel posted by members on your ignore list. I’m not sure how it is implemented in SMF 2, but ideally there would be the option to manually show posts that you temporarily want to unignore. I think it’s better to just see everything and ignore posts yourself.
But I do see that some members will find it useful, so I am not totally against it. As always, this is up for discussion