Ptkay, 100 and 300 error nobody likes. Because the very flight btw Beacons goes between 300 metres and 70 metres there. And what's the point then.
However people comment nevermind what's written in stupid manuals :o), a decent controller in their experience in this equipment tells the plane's position up to 10 metres height. In spite of his manuals, or according to them - that's what is expected of ground control by pilots.