There’s not a 3rd party player to license, because it can’t support things like PIP in IOS, etc. Something like this doesn’t exist.
We could hack together something to work for a few formats, like Channels did, and then transcode the rest but we’d literally be in the exact same boat we are right now, except the ‘few formats’ support might be ones live tv works on, with significant (hundreds of man hours) work.
Blame your vendor for only supporting XYZ format. It’s something they limited, not Plex. Channels, VLC, Kodi, Infuse, etc are ‘hacking around’ their limitations, and at any moment, the rug could be pulled out from under them, which has happened in Kodi and VLC land several times.
Also, it makes supporting stuff like audio codecs a massive burden as well, when you do it yourself. Kodi and VLC has had to do immense amount of work themselves in this space.
Those are literally always the options for any media player, that exists. We’re lucky we have the ability to fallback to transcode. Before that, it just said ‘failed’ and nothing you can do.
Roku gets updates monthly, if not more. It’s one of our most active platforms. Xbox is active as well, and hopefully will be out soon.
Neither of them are ignored platforms, by any stretch. Anything that’s get use and we can find the people to work on them, we do.
TLDR: The more open the platform you use it, the less restrictive it is. You want to use super closed devices like Apple TV? The vendor has purposely limited it. You want to direct play as much as possible? Build a HTPC, or use a Shield, which uses Exoplayer which is open source and therefore much easier to extend and not at mercy and whim of a specific vendor.
PMP is the future, for devices that MPV run on. If your device doesn’t have MPV support, such as Roku and Apple TV, it’s impossible to even consider it as a player replacement, since thats the backend player for PMP.