Connect SaaS VB Studio to OIC Gen3's VBCS

Summary:

We have a requirement to add the VBCS(which comes with OIC Gen3) to the VB Studio provisioned as part of SaaS.

Based on the documentation when an instance is not in the same identity domain as the VB Studio then we could use the Instance Credentials to add that as an Environment.

But there is a note which says that this is not applicable for Gen3 (probably because Gen3 factory API's does not support basic auth)

What are the Workaround ?

Client does not want to spin up a standalone PaaS VB Studio even if its free.

Also note that the Tenancies are different. So this approach may not be applicable :