I see that Plex VR is available for the mate 9 pro and the mate 9 Porsche design can we get the mate 9 approved for download?
This is unfortunately outside our control.
These are the only phones that support Daydream at the moment:
How much if this is just buzz around Google specific implementation, because cardboard another VR apps work perfectly fine. The phone is more than fast enough, however it's only a 1080p screen vs a 4K screen however at that resolution it's hard to tell much of a difference at least with some of the early VR stuff on the phones. I didn't know if there was something to be added to the application list or if it has to be part of the Daydream project. However if there's an APK to be downloaded I would be more than happy to test it out.
You'll have to talk to HTC as to why they don't support Daydream, it may be as simple as "we want you to upgrade your phone" or that they're working on certification or it may not meet certain hardware specs. Don't underestimate the horsepower required to run Daydream for extended periods, my Pixel 2 gets pretty warm just watching a movie for a few hours.
Keep an eye out for updates, Daydream was the first VR implementation but the hint is that if this is successful they may port it to other platforms. If you've got a VR setup already feel free to put in your vote for the next platform, if not I'd be curious to see if Plex can quickly throw together a stripped down Cardboard app (requiring a controller?) just as a more generic catch-all.