I think you are currently best to stick with non-beta v21 and just use your Oculus Desktop app device quality settings (in your case probably prefer Quality). If you want to further improve this use the free Oculus Tray Tool and use its Quest tab to change the encoding resolution to 3664 and then change the global settings to super sampling = 1.2 and asw = auto, and auto scaling = off. This should give you the best results with Link right now imho.
BTW I noticed the audio was quiet when playing PCVR through the link cable. All the settings in windows and on the headset are maximum.
If I use the Quest wireless it's really loud but with link it's like the volume is turned down 30%-40$%. It's loud enough to play but it's still quiet.
Is this a known issue and does anyone know how to solve this yet? Other then that the link cable seemed to work pretty good but need to spend a few more days testing more games before I can give final verdict.
UK: England - Leeds - - RTX 2080 - Rift CV1 & Rift S - Make love, not war - See you in the Oasis!