I can't get the hardware transcoding to work right now either. I just built this server last week, Intel I5-10400 processor and running the latest binhex-emby docker container. I have done all the steps in this thread and added the variables to the container settings (GIDLIST = 18, /dev/dri/renderD128) and even added their APP_UID and APP_GID after the first two alone didn't work, even though I'm pretty sure those are now replaced with PUID and PGID in the initial container settings.
I installed the intel-gpu-tools container to confirm that my system is finding the GPU correctly and it is. I have a DisplayPort Headless plug in to make sure the GPU is active and enabled all the appropriate settings in the BIOS for it.
The emby container still isn't finding the GPU:
I do have a valid Emby Premiere key in place.
So.... now what? Has something changed in recent releases on what the variable names need to be to find the GPU?