Clarifying Page-Level ACL Inheritance

Hi!
I’m trying to confirm the exact inheritance and behavior of Grav’s ACL system across the following layers (and anywhere else I might be missing):

• Site-level defaults (user/config/site.yaml, plugins/login.yaml)
• Groups (user/config/groups.yaml)
• Users (user/accounts/<user>.yaml)
• Page frontmatter (access:)

I’ve read the Login plugin docs and successfully tested examples like:

access:
  site.login: true
  groups: [editors]
  users: [eightysixed]

…but I can’t find a canonical example in the docs showing how these layers merge together.

Older forum posts mention this topic, but most were written before the later Grav 1.7.x updates — and some of those links are now gone.

In particular, I can’t find much on using the groups: and users: keys inside a page’s access: frontmatter in Grav’s docs/the Learn site.

Questions:

1. Does Grav formally merge group → user → page ACLs at runtime?
2. Are access.groups and access.users officially supported, or just respected by the Login plugin?
3. Is login.visibility_requires_access: true still the correct way to hide restricted pages from menus and listings?

Any official clarification or example YAMLs would be super helpful — especially for new users setting up private sections, member areas, or simple editorial workflows. Thanks! 🙂