This is like a Feature - Dev topic, not sure which one it should be in.
Is there a way to modify site settings in a plugin? I’m 99% sure there isn’t, but I’d just like to confirm that.
If there isn’t, can I put forward a suggestion to not make it immutable? Or perhaps, having some API or a way to ‘unlock’ the immutable property of SiteSettings, perhaps?
A possible use case I’m looking at is to the include a list of protected categories to a setting such that it’s easier for the admin to include/exclude them.
Can you first describe the use case from the point of view of the community? What are they trying to accomplish and what makes that hard to do right now? What feature do you imagine solving their need more effectively (regardless of how it’s implemented)?
Then, we can work from there to determine if this is best done in a plugin or as a core feature.
Then, we can work from there to discuss suggestions for how to implement it.