Do you know what plex clients can handle av1 without the server having to transcode?
I started looking into converting stuff to AV1 but only confirmed that my gpu doesn't support AV1 but does support hevc so I stopped there...
I started to convert a lot of my content in AV1 until I realized that my Nvidia Shield devices won't play AV1. My $30 firestick will play them but I do really prefer the Shield. I guess I'll wait it out and hope for a new Shield (it's been 2019 since Nvidia released one) but i'm not going to hold my breath.
IIUC, it's more about the client hardware that determines ability to play without transcoding. You'd have to check the mix of devices you have connecting to it and make a judgement call.