Fix for random freezing in OpenCore Catalina with Radeon VII

I was having issues with my OC system randomly freezing when bouncing audio files from music projects or sometimes when compressing/exporting video from various apps. Sometimes I would sit down after being away and realize that the screensaver just wasn't moving. The system would be completely unresponsive to mouse or keyboard entries and the fans would rev up like they were trying to take off. The only way to regain use of my system was to force reboot.
This fix is courtesy of /u/The-Bloke via this thread but I just thought I'd add a detail I would have found helpful (the previous thread is archived so I can't add to it). Please go through that original post to make sure the same thing is causing your problem before trying anything outlined below.
It turns out the problem is with AppleGFXHDA.kext which handles the audio from the HDMI/DP. As /u/The-Bloke had pointed out, the .kext needs to be disabled. In OpenCore, you can do this with:

<dict> <key>Comment</key> <string>Disable AppleGFXHDA</string> <key>Enabled</key> <true/> <key>Identifier</key> <string>com.apple.driver.AppleGFXHDA</string> <key>MaxKernel</key> <string></string> <key>MinKernel</key> <string></string> </dict> 

 
I'm a complete moron and still didn't know where to put this code in my plist since I had done most of my original edits with opentree or xcode, but /u/The-Bloke was kind enough to spell it out for me. Open your .plist in a text editor, then paste that code under Kernel -> Block. Use the search function to find <key>Kernel</key> then <key>Block</key>. This should be right after the section where you link the kexts you've added to your EFI, and right before <key>Emulate</key>. The only other thing I had in the section I added the code to was AppleTyMCEDriver, but yours may be different.
If you're running Clover this won't work, but check out the original thread where he outlines how to fix that too.
I hope this helps someone at some point. So far it's been almost 2 days of heavy use and no freezes whatsoever. I'll update this if there are subsequent issues.