Correct. ARC GPUs are not officially supported (meaning: We do not ship drivers or libraries with the package). If you install all the drivers to make it VAAPI compatible (like AMD) then it will work for you in that VAAPI driver.
I have a Nvidia RTX2000 Ada Gen GPU.
I am a little partial to it but only because Nvidia does VC-1 transcoding better than Intel. (VC-1 is the codec for most of the blockbusters movies over the past few decades)
