I was worried at first PTP but couldn't right my Stingray which was 18ft 170kg all up. As you go further out on the board you'll soon see whether it flexes too much, if at all and you get an enormous amount extra leverege between standing on the hull and pulling nearly straight down as opposed to leaning out from the end of the board and pulling sideways. Even when I put the righting pole on the stingray for solo righting, I had to go off the end of the board for the leverege.
CATastrophy even though you have the anti turtle is your mast top still sealed and the anti turtle devise, if thats foam is it dry and light not water logged as that bit of weight can add a lot of leverege against you 30ft out.
regards