diag.rom-enable and disables the robot. The command connects to the motors without recalibrating them, because a normal enable would open the grippers at once and drop the items. It opens one gripper at a time so you can catch each item, then disables all motors.
The arms don’t move. They hold the pose the test left them in until the final disable.
After a Mantis gripper test, pass --target mantis. The command then addresses only ID 8 on each selected Mantis bus.