When I upload a new torrent, I noticed that most seedboxes clients are libTorrent, so when I see a peer using libTorrent, I set the Bandwith Priority Group to Ultra-High, Allowance x10 for those peers and tick Force Unchoke. This speed up the initial upload as seedboxes have high bandwidth internet connections.

Could this implemented in Tixati at some point, having categories of Bandwidth settings based on client?

I second this request.

it should be equal for everyone

and addition of specific client workarounds sucks - in 3 years everything will change

you should use categories then - if torrent name includes your favorite release group - and auto assign it to category (see "bandwidth" tab in category properties)