After several hundred hearings, the pattern is consistent. The applications that fail are rarely the ones with weak design. They are the ones where a resident raises a concrete concern about traffic, drainage or light, and the applicant answers with a rendering.
Bring the person who did the work. When a resident asks where the water goes, the engineer of record answering with the actual post-development runoff rates ends the question. When someone asks about the property line, the licensed surveyor who set the monuments answering ends that question too.
The corollary is that the hearing is prepared for during due diligence, not the week before. If the constraints map is honest, the answers already exist by the time anyone asks.