I'm a qualified referee with ~5 years experience. I have no idea how to operate one of the digital boards, I've not used a comms kit and I have no real idea of what a 4th official actually does to be honest! I was also under the impression that all referees at that level are observed on every game - couldn't the observer come down and fill that role?
Sorry, observers are specifically barred from officiating. If he had come down the whole of their observation would have been voided!
And before any of the L4's I know say it - "when has an observer done anything useful at a football match!!!!!"