B2C Support for on behalf of (OBO) flows

Hi all, 

this is maybe a question for the Entra ID product group.

Does anyone know a rough timeline when there will be support for On-Behalf-Of (OBO) token flows in Azure B2C or Entra External ID? According to https://learn.microsoft.com/en-us/azure/active-directory-b2c/access-tokens, at the moment OBO flows only work for applications registered in Entra ID. 

Kind Regards

Chris