admin I have NOT been able to play the HEVC 5400x2700 videos. I have tried converting the HEVC to H.264 for the higher resolution, etc. However, I have not noticed any reasonable difference between the converted videos to your standard 3840x1920 H.264 videos, other than them being about twice the file size. I always download Oculus Rift versions instead of GearVR versions also. Although sometimes there is no difference between the two, generally Oculus Rift downloads are better quality than GearVR downloads. So my standard process is to download the Oculus Rift 3840x1920 H.264 videos. And those seem to be better quality than others I've downloaded from other websites also. But even on other websites, I always download Oculus Rift versions.
And I definitely spent hours and tried ALL different options with the Lola Myluv scene because she is just.... WOW! So gorgeous and hot. But I'll be sticking with the 3840x1920 H.264 versions probably, unless you can get higher resolution H.264 videos on your site.
I use Pigasus and DLNA to play the videos. I was using Plex DLNA for a while but discovered it transcodes everything while playing the videos. So I switched back to using PowerDVD DLNA server with Pigasus because I think that does not attempt transcoding, but I may be wrong.