I don't know if anyone is interested, but I have several videos running on my nexus5 now, using UTmedia player (available in Open Store) and running videos (reliably and smoothly) in specific mp4 h264 format. I have also converted other videos to this format and they are running successfully (although better if resolution is 720p or lower). UTmediaplayer also seems to play the internal movies pretty well, too.

If you are in N. America, it is much easier to find/buy a used Nexus 5 than many of the other devices if u want to save money. Pinephone is good if u want to buy new and I believe u can choose to have ubports pre-installed.

Congratulations on the the new OTA-12. I just got it last night and so far I'm loving all the new features. I was pleasantly surprised to find there is a new 'charging' light on my Nexus 5, which was very cool. The new side-bar/home screen/phone-top looks great and I like the navigation. (Although now I feel I have to update my dated background). Thanks for all your hard work.