andypat wrote:... neither planner nor controller were aware of any UKUL guidance on winning times sorry...
Some areas lend themselves to longer courses, whereas repeated laps of a smaller area will get tedious no matter how nice it is. A two-round sprint can be a good way to use two small complex areas that are separated from one another. And an evening urban race that's squeezed into a busy weekend should probably be shorter than a stand-alone event: few people will want to race for an hour or so if they're running a level A regional champs the following day.
So think about the terrain and the context, and then just plan some good courses.