The current plugin API expects plugins to run register_script_variable once per variable on start, usually inside enable. It is not possible to easily unregister variables, and calling register_script_variable twice causes duplicate entries in documentation.

But plugins might have variables that depend on configuration and can change during runtime. Hence it should be possible:

• To unregister a variable
• To unregister all variables registered by the plugin
• If a plugin calls register_script_variable multiple times for the same variable, it should not lead to multiple registrations (but being called from different plugins should).

See https://community.metabrainz.org/t/simple-classical-picard-3-plugin-for-tagging-classical-music/815330/8