Are you a proud owner of multiple Vectors? Great! Amitabha Banerjee has created a custom Python SDK that has Amitabhas machine learning routines implemented so one Vector is able to recognize another one.
You can read about it in a Medium post. In that article he also asks for help testing this out, so if you actually own multiple robots, please have a look at it and try it. There is more information on the Github repository page of the Python SDK project. At the moment this can only recognize another Vector, not individuals, but that is planned for the future, based on their eye color.
And as he correctly says in his Medium post: If only Digital Dream Labs would have delivered an OSKR in a halfway usable state, this could most possibly implemented directly in the robots themselves instead of via an external SDK. Vector recognizing another Vector was promised by DDL a long time ago and then seemingly silently scrapped. So here again someone else did what DDL could not.