Downloaders keep adding to their queue, hog slot forever

I'm having a problem with some people hogging download slots. They stay within my limits for the number of files queued at any given time, but they are very diligent about adding more to their queue before it empties out, so they just keep downloading forever.

I don't want to just keep adding upload slots, because then each slot is too slow. I don't want to forbid them from downloading, either.

I sometimes delete all of these users' items from my uploads queue in order to bump them to the back of the line, which helps free up slots for all the people who just need one or two files. But since these guys are online all the time and I'm not, every time I start up the client, there's a good chance that they will end up near the front of the line again. Once their downloads start, they've apparently got that slot for the entire rest of the time I'm connected.

If I delete just some of their files from the Upload queue, then for some users the deleted items will reappear in the queue within a minute or two, and it's as if I hadn't deleted them at all. For other users, either no files or maybe one file will reappear in the queue until after one or both of us reconnect, at which point the whole set comes back.

Maybe I'm not remembering correctly, but didn't SoulseekNS handle the queue a little differently? At least, I don't remember having this problem before switching to SoulseekQt.

I thought the way it used to work, if someone added more files to their queue, those files would be at the back of the line, behind the files that other people added in the meantime. Thus a downloader couldn't really hog a slot so easily; they'd get their first batch, and then even if they queued another batch, when the first batch finished, the slot would be made available to someone else (unless no one else was waiting).

Likewise, if I delete files from the upload queue, I expect those to go to the back of the line if they're re-queued.

In SoulseekQt is there anything I can do to keep people from permanently hogging my upload slots?