plex does not transcode INTO 4k, so any 4k transcoding will be to 1080 or less, SDR, and x264.
see #1, if the 4k/hdr video is trancoded for any reason, you lose both 4k and hdr, and it will be in x264, even if your tv is 4k.
safety equipment is generally required in any ‘insert any dangerous sport or activity here’ and is most safety equipment is the player’s (or perhaps the team’s) responsibility not the sports responsibility.
plex doesn’t require you to use any 4k or hdr or force you to transcode them. If you are not direct playing 4k/hdr then that is on you.
I have tried this with and without the display type set to “SDR” and every time it is washed out. Details: I was playing a 4k HDR video on an Apple TV 4k on a SDR 1080p display with the SDR setting and with the new player enabled. I verified there was no transcoding. It DID work when I used Plex Media Player on the Mac. This is with the latest version of the Apple TV app and PMS as of 5/6/19.
