Can you install Hass app on FiiO R7/R9?

Considering an upgrade from my Lenovo smart clock for my bedroom. I’m really charmed by the FiiO streamers R7/R9. They run Android. However I think it’s a locked down version (just like the Lenovo SMart Clock). So I was wondering whether someone has experience with these devices. I have a few questions:

  • Can you easily (without any advanced hacking) install the Hass companion app on this?
  • Is the screen always on? I.e. If I turn off the streamer, will the screen remain on, or does it go blank?
  • If it stays on, can you dim it to very low brightness to not keep you awake?