Go around pop up
One situation it’s necessary to keep a really good lookout on an OHJ is when descending dead side and someone on final goes around. Sometimes an early go around on final can pop up to circuit height by the time the aircraft reaches the numbers at the upwind end. This can place it just where the descending aircraft is aiming for and at about the same time if both pilots are very unlucky.
I don’t recall ever hearing any discussion of the need for a go around to stay below circuit height until clear of the numbers or aircraft on an OHJ to watch out for a go around in any training material I have seen.