We looked at having one user act as race committee for multiple divisions but this approach isn't really compatible with VR custom races. It could work, probably not very well.
Our solution is to put one RC rep in each division of 20 boats, we're calling this person the host. Host duties include creating the race, starting the race, and taking screenshots of the results before they disappear. The host can race too.
A lot has to happen outside the game like registration, setting divisions, sending out race codes, collecting results from hosts, and scoring the series. Not ideal but it works.