Well look at it this way. The Mozzies with spinnakers will be sailing windward-leeward courses, so unless all the other classes are happy to do the same, there will be different courses sailed.

The NoR doesn't mention that there will be an overall result, but if there is going to be an overall result (not really necessary but YV liked to have one in the past), the club will have to figure out a way - such as using the GPS co-ordinates of all the marks to work out how far all the classes have travelled and adjusting their time accordingly. Either way it's something for the club to deal with.