I have been building a GPL v3.0 licensed user script for use in browser extensions like Greasemonkey, Tampermonkey, Violentmonkey, etc. I would also like to state in the documentation that it can also be used in the Userscripts Safari extension as well. However, I want to avoid violating the GPL's requirement against linking GPL code with non-GPL software, and due to Apple's legal requirements, Safari extensions cannot be released in the App Store under the GPL.
The Free Software Foundation says that "A main program that uses simple fork and exec to invoke plug-ins and does not establish intimate communication between them results in the plug-ins being a separate program" (source), which means that they don't both need to be GPL-licensed. Does a user script count as an example of this?
Any clarification about this would be greatly appreciated.