I’m not aware of the specific packages needed by name.
I do think you need to add the runtime drivers for the card.
Just because kernel support for the card (on the PCIe bus) is complete, it does not mean the kernel also includes HW transcoding drivers.
The card can be used for solid modeling, gaming, or video.
It seems logical for the user to add whichever function packages he/she wants to use
It might be a good idea to search both the forum and google.
Here’s a forum post confirming the Arc GPUs work with Plex.
