So transform service just wrap expansion services. So change of behavior should be similar to the change of behavior of the Java expansion service.

Regarding, cross-version usage, I think what could break is use-cases that assume a schema from a old Beam version while trying to use the new Beam version for expansion. For example, hand-coded wrappers in customer's side. We are updating the affected Beam provided wrappers so I think the chances of someone running into issues due to this should be rare.