You're right, Montana. It should only fault out if it's under normal operation. DLM is disabled on all forms of engineer mode. There might be a better, safer way of doing it. if the TOC run box on the cab top is wired directly to the main controller, you could just use the bypass switches and then jump out the connections for the TOC run box (making it think it's on TOC inspection). This method is actually safer because if you accidentally leave jumpers behind, the lift will remain in engineer mode and not attempt to run at all.

If the above applies, follow this video (please note, this is not an Otis controller, but the concept should be similar). Start from timestamp 2:22. https://www.youtube.com/watch?v=SIwwCYa-M_4