Playlist looping

By default, mpv doesn't offer a key bind to toggle playlist looping. Consider adding the following to your input.conf:

$your_keybind cycle-values options/loop-playlist inf no

See the reference for more information.

CLI Library Management

pmcli does not and never will offer an interface to create, delete or in any way modify your Plex libraries. That is because this is already possible with official command line tools.

If your PMS runs on Linux, make sure to read the bottom note on LD_LIBRARY_PATH from the above link and that you're running the scanner as the same user running the server instance.