I know this has also been written here in the subforum for desktop players. I will raise it again, as I just stumbled on it again.
- SD/DVD content = 576i/480p
Playing DVD content with Plex HTPC and with resolution switching enabled can lead to a broken/stretched/malformed image. This is not an issue of Plex HTPC to select the correct resolution, no, its a problem with modern operating systems and TVs. They don´t like these low and interlaced resolutions.
Solution:
Let the user decide, whether he wants to allow Plex HTPC to switch to such low resolutions. If the user does not want to do so, just keep the current resolution or switch to a lower mode that newer TVs support like 1280x720 and let Plex HTPC do the rest. That way, we can still watch our DVDs without having to manually disable resolution switching every time before playback.
- 4K and above
As far as I know, resolutions above UHD (3840x2160) are not used. Looking into the future of higher resolution TVs and content, it might be useful to also allow higher resolutions to be selected. In my case, I have some 4096x2160p content and my TV supports this mode, but every time I watch them, the TV is set to 3840x2160p…
Solution:
Let the user decide, whether he wants to allow Plex HTPC to switch to such higher resolutions or just do it by default.
Note on “let the user decide” - this doesn’t have to be in the settings inside the app. A simple configurable option inside the plex.ini file would be fine! 
Thanks!
