The current Management API is only partial idempotent. E.g. resourceServer. If you create the resourceServer again, it can update everything except the audience. Another example is custom domain. This one is not idempotent.
Use-case: We’re using Pulumi to set up Auth0 as IaC. For that, it would be really useful if the resources can be fully idempotent updated. Think about your domain URLs. You could do this simply by changing one central config, and IaC would update all relevant resources (Auth0, DNS etc.). This would make such changes fast and reduce the risk of this change to a minimum.