anon,
Good advice.
Competitors should also be aware that while there is usually a pre-event published schedule of events in smaller regional competitions some events might be cancelled due to lack of entries. Also, where there might be only one entry in a particular class the judges might ask the couple to dance their class with the next higher group so they don't have to go on the floor alone. In my experience this is most likely to occur in a newcomer adult or junior event.
Both of these items can drastically change the appearance of events.
However, as emcee and time permitting I will often insert "general dancing" for the public so individual classes dance as close to published times as possible.
Best to arrive early.
OB