This is, and will continue to be, an evergreen issue until it is implemented, Apple deprecates their support, or it is otherwise superseded.
My original request is now almost 3 years old, a span of time which should have produced several cycles of development, testing, bug reports, and other work relating to this.
It is notable that the WWDC sessions relating to AirPlay 2 appear to have been pulled from the official site, at least I can no longer find active links to examples I’ve cited previously. To me, this lends justification to pause advocacy for AirPlay 2, at least until WWDC this year.
That said, the architecture of AirPlay 2 provides for the ability to remove the iOS device from the data path during playback. Plex is in a uniquely optimal position to take advantage of this by pointing the AirPlay 2 speakers at a Plex HLS server to fill the buffers. By only supporting AirPlay 1, the iOS device must keep its network stack persistently active to maintain the data stream during the entire playback function. Even if it weren’t setup to point to the server, preloading entire songs into an AirPlay 2 buffer from the iOS device directly would be much more energy efficient from a bit-per-watt perspective.
Finally, another feature sorely missing is iOS Shortcut functionality. This is tangentially related to AirPlay 2, but should be obviously useful in its own right.
