Is there a way to ignore a user?
You can block PMs from a user, but on the forum, I don't think there's a way to ignore a user.
EDIT:
Maybe I'm wrong about that last part...
See the posts below.
Ask TK? Think she had some css something-or-other to do something along those lines.
Or maybe I’m just hallucinating…
No, you're not hallucinating.
Toykeeper knows how to block something on BLF, but I don't remember exactly what.
It may have been an ability to block a specific user.
Wow...
I totally forgot about that!
...
EDIT:
If the instructions worked in early 2019, they should still work now, though I haven't tried it.
I believe BLF is still on the same version of Drupal as in early 2019.