Colas said :-
Of course, maybe the SUP board will be destroyed in 10 sessions from the moment forces involved...
The only issue I had was 6 months ago when we attached a foil to a stock Sup and the leggie got wrapped around the mast and tore it out. Lucky it was clear water and shallow and we got it back but since then we are making boards specifically designed for the foil and no failures.
The standard mast mount for a Sup for is 21 inches from the tail but if you want to windsurf foil on the same board you will need to mount the mast point only inches from the tail .This presents a second problem that the fuselage must be longer to get the rear wings back to stabilize. All the windsurf foils have a lot longer fuselage so I question that the Naish foil in the above video will be the one for both Sup and Windsurf unless they have an interchangeable fuselage. They don't show much windsurf foiling in the video.
All that aside I reckon windsurf foiling looks insane and wish I was a windsurfer but I'll stick to my Prone board ,Sup & Kite no more room in my shed.

Check out the mast point mount and completely different foil design by Robbie Naish Windsurf foil in this video.