I wanted clarify my comment on crossover, but maybe some more details just to avoid confusion: what inspired the comment was my hope to be able to have one board do it all. I had custom SPG made - at around 90-95L it is well within the realm of reasonable for my 70kg, and I had hoped to be able to wing, and sup DW with the same board.
The outcome - excellent for winging, very fun for gutless prone, great for sup DW, but the issue is I struggle to get faster foils going in poor conditions. In ideal conditions it is excellent, and with a big slow pump foil it is effortless. In suboptimal conditions or with a faster foil, it doesn’t quite cover it. I should have gone 10-15L more, and maybe 6" longer.
So my 2c, if you are at all serious about SUP dw then go for the extra volume and length.