I've implemented support for setting defaults for new members (https://gitlab.com/composr-foundation/composr/commit/3f7d7cb57208165c8c18567bd6b7f23226d39010).
I haven't implemented support for mass-resetting for existing users, because I think that's questionable, and definitely less important. For example, what if a user has a more sophisticated setting already? What if there's a GDPR concern about opting people into things? What if you want to do it for only certain usergroups? I think this is something left out of the core product, people can do what they need with custom scripts in the rare case they need it.
I also haven't implemented support for setting defaults for individual categories (e.g. a particular news category), just the main notification types.
I haven't implemented support for mass-resetting for existing users, because I think that's questionable, and definitely less important. For example, what if a user has a more sophisticated setting already? What if there's a GDPR concern about opting people into things? What if you want to do it for only certain usergroups? I think this is something left out of the core product, people can do what they need with custom scripts in the rare case they need it.
I also haven't implemented support for setting defaults for individual categories (e.g. a particular news category), just the main notification types.