Enable mechanism to update/reset externalID (to seamlessly change IdP with SCIM)

Description

We deployed our users with SCIM and are currently changing identity providers. Okta, using the built-in provider for Monday, publishes their unique identifier to the externalID field in Monday. This allows conflict resolution in cases where the username may change (e.g. user name is the email address, email address is based on name, and a name change has occurred).

However, after moving to Entra, we are unable to change the externalID on existing users to match a field that exists in Entra (they default to the original email prefix but also could using the objects UUID/GUID), as any attempts to change result in an error message stating the externalID cannot be changed.

Even if you prefer to prevent changing this value during normal operations, an option in the portal or via a support ticket to reset the value should be provided.

What are you trying to achieve

To maintain the value and purpose of the externalID with SCIM after chaning identity providers.