This seems like a lot of discusion for something that is pretty straight forward.

If the boat is measured and does not violate any formula limits then it is a fully compliant F16. Theoretical performance has nothing to do with it.

For non-national/World level racing, where full complaiance should be mandatory, bring on anyone who wants to race. A well sailed SL16 will end up beating a poorly sailed F16, and with the exception of a hand full of people in the world this will be the case on any boat.

I prefer to race everyone together to get the most out of the experience in everthing but the highest level events. There will be combinations of sailors and boats that are very evenly matched no matter what is sailed. For the higher level events where compliance is being observed if it does not measure then it is out. A F16 may be competitve with the F18s in theory but it is way under weight and will never be "in complaiance" to compete in a high level race. If a crew on a SL16 wants to sail at Zandvort and their equipment measures in then they are welcome. There is no "invite". For local stuff if you are getting wrapped up in who you sail with and what boat you sail, please leave or go get on a mono-hull.