Beat me to it. My square head is bigger than yours, ~2.36 m, (about the only thing I can brag about) so I will let you know how it goes, when I can get around to it. I was planning on 120 degree winglets as well, pinned to the gaff batten somehow.
Decided to go really small and see what happened. This thing is probably 250mm f-a and CL to tip 100mm, (there is another out the other side) I got some Vee-blocks made (3D printed) that hold them all at 120°.
You mean a bit like this:Further the way that they have the top aft edge up above the fwd (main-head) would either exacerbate of negate the vortex, I don't know which one without looking closely at it, which I have not done.
I am all for looking horny....49er has a SCP of about 71-72kgs.
It has a (working) sail area of 22m².
So those sails are loaded 3.27kgs/m².
DP has a SCP of approx 150kgs
Has a (working) sail area of 45m²
So those sails are loaded 3.33kgs/m²
Sure, a lot of that load is in the bottom 1/3, as it should be, main and jib (as in slot), well end-plated yad yad yad.
So if we had spirals happening on DP, and all other things being equal, then very probably there will be spirals on a 49er, so some level of wing-let would probably work very well on a 49er.
The WING also has wing-lets and the feedback there was significant.
29erC in China, had wing-lets also, but I have no data/feedback on that.
FX, down 25% on SCP, and probably down that in SA, plus shorter ARM so very likely to benefit from wing-lets. (more so that 49er)
I14, less likely, more sail area, less SCP, so less loading, so less pressure differential.
Skate, huge SCP, compact sail plan, highly probably benefit from wing-lets.
Current 18teen, I'm guessing is likely to be similar to the I14, also on following them the upper leach "hangs way off" as it would have to, so less likely to benefit.
Before everyone jumps on the band-wagon, I don't have any "proof" that they do anything yet other than look horny.
All we have is GT and (the other) JB (jimmy Beck) saying there are less spirals