I build a simple nas system for my archive with pi zero w bu I know plex not supporting on this device.
We need lite version for low powered cpus such as pi zero w’s armv6.
Simple features enough like;
File indexing,tagging/matching
Subtitle download.
Audio track selection.
Tv app support >> that is important
No need transcoding,dlna etc.Direct play working well on local network.
I can make these with lighttp+php+ffmpeg+sql but your system very stable, I have to start from zero. And I have no knowledge about tvapp programming. I’m not a coder just a noob script kiddo 
I made samba share, index my files and share with kodi’s upnp/dlna feature.
I want to make it without use my laptop, but my pizero w
I think PlexLite version can be made easily.
Please think about it.