I do feel strongly that a TRI fin , or twin, aides upwind greatly.
a BIC Presto, added the side bites, cut down the trim box center fin, tried different sizes, most were ok.
had a brain wave, tsumi actually , to add the center fin,its removable, rather large..but then they are ...mostly.
largest consideration was where to place it.
This entire application was for my 8YO neighbor Sarah. I have sailed it , since the shape is so old, that takes more getting used to than I see fit.
She has graduated to a ProKido Formula .