Good points ChristoffM.
I think if you ventilate the center a little, you lose a fraction of lift, but lift is more or less still balanced across the foil, so you could usually recover.
Ventilate one tip but not the other, you may have off-center lift, leading to a crash, no?
With anhedral, tips stay immersed, ventilation would be starting from the strut in the center, anhedral could help that bubble just flow aft off the wing, rather than flowing spanwise to tip and creating unbalanced lift.
I think dihedral would enhance flow along the span and also allow the bubble to expand due to lower pressure the farther out the span it progressed.
Does that sound plausible, or is it just my fantasy?
I think, a ventilation at the center, of a swept wing, is by far the worst of all
As the flow (ventilation) will continue across the whole wing very rapidly then.
I have no idea if a ventilated tip would cause a "yaw" effect leading to a crash, or not.
You may be right, or it might not mean anything - as when riding a foil, it is amazing how stable and rigid it is.
A wing with anhedral, has been used "often" in airplanes, in order to minimize tip vortices (induced drag).
But, the downsides in handling are too big, so mostly used for fighter planes because of its instability, thus very agile.
Meaning, you can not use these experiences for ANYTHING at all.
In theory, you would make a wing seem higher AR, by having anhedral.
But the downside is, the lift is not perpendicular anymore - just like a C kite is never as effective as an SLE kite or foil kite.
So not sure this is the reason...
Handling, and the ability to ride without ventilation issues, would be my best bet
But, a very new sport, so you never know if the current most used solution is "the best" for most, or just how it is right now (and thus many follows)