Protect a folder from deletion without protecting children pages

Hello,

In many grav sites, I have the following architecture:

• page A
  • children 1
  • children 2
  • ...
  • children N

I would like to prevent a user to delete the page A by mistake, as it deletes all the children pages. If I edit the CRUD on page A with :

permissions:
    groups:
        defaults:
            delete: false

The delete button in admin disappear on page A, and that is perfect. But it also disappears on the children pages.

So I need the children pages not to inherit permissions by default. I have tried many different solutions for that.

• Editing the root page doesn't seem to have an effect.

• Modifying the template of the children pages with:

  YAMLCopy

  form:
  fields:
  tabs:
    type: tabs
    active: 1
  
    fields:
      security:
        fields:
              header.permissions.inherit:
                replace@: true
                type : toggle
                toggleable: true
                default: 0
                label: Permissions des parents
                help: PLUGIN_ADMIN.PAGE_INHERIT_PERMISSIONS_HELP
                highlight: 1
                options:
                  1: PLUGIN_ADMIN.YES
                  0: PLUGIN_ADMIN.NO
                validate:
                  type: bool
  

to change the default value of the inherit permission. It results in an odd behavior : the inherit permission field is still present in the admin and also the new field, and there is a mirrored behavior : when i change the value of one of these field, the other field is changed as well. Anyhow, the delete button is not present.

Do you have an idea of what I can try?
Best
n