not sure whether you knew it or not - but peer id spoofing (as uTorrent) was added because it was being banned on several trackers.
Take a look at the bug to see a few examples
https://bugs.launchpad.net/qbittorrent/+bug/497450
I think most private trackers allow Ktorrent and Transmission as they are considered defacto.
I think most private trackers allow Ktorrent and Transmission as they are considered defacto.