Not really when it's chronic and he's been doing it for months with the intent of disrupting the forum. There needs to be a penalty that is more severe and which suits his willingness to destroy a forum and it's membership. Sorry but I have no sympathy for a chronic troll given banning his troll accounts doesn't seem to work as long as he has a sub and just makes new ones.
If it's not breaking the TOS then they need to change the TOS to cover this type of behavior. Sorry it's not acceptable.
I do the same and I've put the accounts on ignore. The bottom line though for me is it's not worth sorting through threads and having to try and find ones he's not bumped to stir the pot. It's a lot easier just not to spend time here.