It’s very similar to what I’m seeing too. Like I said in the thread about video stutters on the 3rd gen ATV 4K, playback is noticeably A LOT smoother when using this new beta build, but not perfect. I can still see light stuttering regularly. Of course, especially during panning scenes.
So far I tested mostly with files that were h264, 1080p, SDR, 23.976 fps.
And like you mentioned, everything is playing fine in Infuse (and for what it’s worth, everything was also playing fine in the Plex app before version 8.18).