Very positive news! I just did some further testing and it appears that I am no longer seeing issues on my Ryzen 7 5700G in the Windows version of Plex Media Server. I ran my typical battery of tests with the Lord of the Rings: Fellowship of the Ring and Jack Jack Attack test scenarios and neither exhibit the pixel distortion that I had reported just over a year ago.
The fantastic news here is the issue appears to have been fixed at least for Windows users, meaning Ryzen APUs are fair game for a Plex server that is running on Windows. I am not sure if this is thanks to the Radeon team or Plex team, but my hat goes off to each for their ongoing efforts.
That said, things are not all hunky dory in Linux-land. I do, however, see that there is quite a bit attention now coming down the pipeline for VAAPI there thanks to the newfound efforts from Plex employee @ChuckPa here:
I will keep my eye on my 5700G build to ensure this bug is completely squashed but up through even 4K streams seems to be playing flawlessly now. I will report back (you can guarantee it!) if I see anything unusual rear its head.
tl;dr: Video Core Next, particularly Video Core Next 2.0 and above (meaning Ryzen 4000 APUs and later and 1st Gen Navi/RDNA 1 discrete GPUs and later) that were impacted by a pixel cloud issue are tentatively all good in Windows for hardware encoding.
EDIT: Removed images with personal server information.
