Certainly at Sherburn deadside joins, at 1500' QFE, are done.
For example, returning to the field from the East, via Selby (normal routing into the Church Fenton MATZ from that direction), if the traffic is on the tarmac runway 29 (left hand circuit) or the parallel grass runway 29, the easiest join would be deadside to that runway.
The principle is to keep a good lookout both aurally and visually.