1: I TAKE ZERO RESPONSIBILITY FOR WHAT HAPPENS, ALL I CAN SAY IS IT WORKS FOR ME

2: You will need an active displayport to HDMI 2.0 adapter (mine is Cable Matters)

Download Win10-64Bit-Radeon-Software-Adrenalin-2019-Edition-19.8.2-Aug26 (google it)

1: Download Radeon-Software-Adrenalin-2020-21.4.1-Win10-64Bit-Apr20 , these are the last decent drivers for all R9 and HD 7000 GPUs, the one that came after has microstutters and a performance degradation.

2: Download Custom Resolution Utility https://www.monitortests.com/forum/Thread-Custom-Resolution-Utility-CRU?page=369

3: Down AMD/ATI Pixel Clock Patcher https://www.monitortests.com/forum/Thread-Custom-Resolution-Utility-CRU?page=369

4: Install drivers

5: Plug in your WMR headset once, then unplug.

6: Run ATI pixel clock patcher

7: Restart PC

8: Open CRU

9:Click on export in the lower left and save that file as "backup".
YOU WILL NEED THIS IF YOU MESS UP

10: Navigate to your MR display details



11: Click on the CTA-861 entry in the Extension blocks section


12: Individually click on "HDMI Support", delete it, click on HDMI 2.0 Support, delete it, click on the 60hz resolution, delete it ONLY INSIDE THE CTA BLOCK (don't forget to save your changes)

13: Click on restart64.exe inside the CRU folder - this restarts your GPU driver

14: restart your PC

15: Go to WMR settings, set to 90hz

16: Enjoy.

PS: This will break the VR preview inside the WindowsMR app, not that it matters because all the good stuff is in steamvr anyway.

This problem has been driving me nuts for a whole year, I thank my unnamed friend who triggered my autism and inspired me to throw caution to the wind to fix this

also thanks to this random youtube https://www.youtube.com/watch?v=sGBqy9q9Uos channel for getting me started
also AMD driver dev team can go die

EDIT: Just ran with these settings all day in VR Chat, it works!!!