The simple answer is no ProvisionPoint cannot exceed the organisation level, but first you need to understand how external sharing works in Microsoft.
External Sharing Levels (Microsoft)
External Sharing has two configurable layers in Microsoft:
Organisation level
Defined in the SharePoint Admin centre > Policies > Sharing is the default for every Site created. The Site will get the most permissive sharing setting.
Site Level
For each Site the External Sharing permission can be changed, but cannot be more permissive than the organisation level.
This is managed in SharePoint Admin Centre > Active Sites > Policies > External Sharing
As an Owner of a Site you can manage other sharing option for each Site but the sharing permissions are only manageable via the Admin Centre.
What does ProvisionPoint Do?
For each Service Definition you can:
- Leave External Sharing Disabled to use the Organisation default. It will use the most permissive permission in the SharePoint sharing policy.
- Enable External sharing to define the Site level to be applied without access to the SharePoint Admin Centre.
- Set the Site level Default to be applied to all Sites created. This should never be set to a level above the organisation default*
- Allow the requestor to choose the site level to be applied. The options list should never allow a level above the organisation default*
*If the level selected exceeds the organisation level, the job will fail to create, and will show an error highlighting this.
This is how ProvisionPoint will never allow a Sites external sharing to exceed the organisation default.