Let's take this spam-comment for example: https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=206544#c6
I've tried to remove it, or mark it as spam, or report originator as spammer but I could not make it.
All that I've found is "Spam" link at the header that leads to https://bugs.freebsd.org/bugzilla/page.cgi?id=searchspam.html
Its form finds noted commend searching for spammer's email but proposes "to block the user and delete all bug reports". It is not clear if it really would remove the PR or just a comment. It is not clear if it would block spammer's account or reporter's.
There should be a way for any @FreeBSD.Org Bugzilla account to mark/block distinct spam-comment and its originator.
I've had some thoughts around anti-spam improvements recently. I'll collate my notes and add them here