Thanks for all the useful informations. In my current setup I use a Proton vpn tunnel on a mikrotik router to route all the traffic from my torrenting machines through it, the only problem is that the router doesn’t support NAT-PMP which is used by Proton to open ports on their side of the tunnel. Is this a problem? If I understand correctly PF does not influence my ability to download but only my uploads (without PF my files can’t be accessed via TCP I guess). I don’t think I need PF because I already had to limit my uploads because of my shitty internet connection, in good days I have 2Mbps upload, this limited bandwidth was always saturated by qbittorrent. I know that it’s not fair p2p but otherwise I couldn’t even use my internet.
I’m asking for confirmation here, when I’ll move to a place with fiber I’ll change my setup for sure! Or maybe I’ll go through some load balancing shenanigans on my network and re-enable uploads in some way…