Hardware accelerated HDR Tonemapping is working as of Plex version: 1.23.0.4497.
Weird graphics glitches still occur if using HDR Tonemapping below the 1080p HD High setting
I'm running an Intel i5 11400 with a UHD 730
1. Create a file on your UNRAID flash drive under /boot/config/modprobe.d called i915.conf
2. paste the following code in the conf file you created
options i915 force_probe=4c8a
options i915 enable_guc=2
3. Reboot your server and you should be able to turn on Plex transcoding in your docker
No need to update your UNRAID version