^^^ you can't run both on the same day one after the other
Often the seabreeze is not in until 3, and you need a few hrs after the race for sweeping. If somebody was really missing properly, it would not be long before dark. It is already the case that they won't start a race after 3 - 3:30 or something for those reasons.
And yes they pick a lot of windsurfers out of the water or retire to the beach as it is a very hard race.
as to going together, you can't run a up to 200 windsurfers and even a handful kiters on that course

the start line is like 100m wide and the start alone (with 60 kiters) will be very very difficult on Fri.