I think, when you get a bit of experience with the techniques we are suggesting here, you will be sailing upwind with these semi and former pro formula sailors and then you will see that they indeed use the same (or something very similar with the same dynamic) techniques to go upwind as well. They've probably never analyzed how they do it, but they sure know how to do it. Biggest giveway when watching them will be the upward curve of the front foot toes. It's very hard to push down and curl your toes up at the same time.
Hope this helps,