I recommend you start off with your Link cable. It’s pretty easy to setup and I get great results using it with both my Q3 and QPro. Your 866 link speed indicates that your router is an older wifi5. Newer wifi6 (not necessarily 6e) tend to perform better. I changed out my old wifi5 router +1 years ago and it made a big difference with both Air Link and Virtual Desktop.
For Link settings I suggest you refer to the settings I posted earlier this year and maybe mod these to suit your PC specs (always a good idea to include this btw). Like everything VR, setup and settings make a big difference. Good luck mate and cheers.