Using ACLs is a great idea. It works well for calendars.
Like with calendars where you can share only date/time, you’d need to be able to share only the whitelist to other users as your address book could contain personal items which you don’t want others to see, but still apply to their whitelists.
For now, I’ve copied the whitelist generated from my main user (with the populated AB) as a manual rule in rspamd settings map so the function is working but isn’t dynamically updated. For simplicity, could there be a way of aliasing an existing whitelist for a domain?
A rule that takes ‘whitelist_jamesblahblah’ which is applied to ‘email@example.com’ but then apply to ‘*@blah.blah’ much like the manual whitelist entries in the domain setup. To achieve what I’m after, this would need to be cross domain too.