Brilliant answered two quetions no one could really answer and that was the tack strap and the built in clue having it either open or closed. My new evo4's should be here tomorrow yeha!!!
So I see Antoine's advice vindicates some posters on this thread from a year ago.
www.seabreeze.com.au/forums/Windsurfing/Review/Neil-Pryde-RS-Racing-EVO-III/