How to ensure only one MPV window plays at a time, and pause the previous one when a new playback starts?

[zDEFz]

I'm trying to create a script that ensures only one MPV instance plays at any given time. When a new instance begins playback, it should pause any previous window playing.

I'm using the following approach:

1. Write the Wayland app ID of the current MPV instance to a shared control file.
2. Other MPV instances check the control file and pause if their ID is not allowed.
3. I'm using the pause property and wayland-app-id to manage control.
4. However, the script doesn't seem to work as expected. Could someone help improve this approach or suggest a better method?