ECB - Establish new Call-ID for 'internal' call

I have a scenario where an SA is sending calls to the ECB that would be considered 'internal', which the ECB then routes back to the same SA.  Since the ECB has no dialog transparency, and therefore the Call-ID is being passed, the SA sees the inbound leg as a loop and kills the call. Can I create and HMR to match against the originating SA IP and manipulate the Call-ID? I know this is against the RFC, but not sure what else to do if the ECB doesn't support being a stateful proxy and the use case is actually