This feature request is obsolete, because Plex Media Player is deprecated and won’t receive any updates or bugfixes.
The currently supported dedicated player apps
“Plex for Windows/Mac/Linux” and “Plex HTPC” are using the open source player mpv as their “engines”. This can do pretty much anything that MadVR can do, but on several OS platforms instead of just Windows.
It provides a similar level of customizability of its visual quality and postprocessing. HTPC Tips and Tricks
