So I've still not found out what the actual boat number is (insurance company weren't actually that worried given it's only low value) but I've decided to fit an adjustable forestay (used to use it all the time on the Phantom so nothing new to me).
I'm not familiar with the Supernova though - how solid is the deck surface? Can the cam cleats just be screwed into the deck, like they are on the Laser for the cunningham and outhaul XD fittings, or do they need bolting on with washers underneath? Rest of the system is straight forward enough - going for cascade rather than the multi-pulley block system as I suspect you'll be able to see the bigger movements better when sitting back in the cockpit (plus I've already got an abundance of single pulleys ).