I come from a hand-flush background and was surprised to learn some people use their feet. It seems a bit awkward to me, especially in a skirt -- yes, I went out to experiment -- but I think it is a "to each her own" kind of thing. Different isn't bad. I would think each side could visualize looking at the fixture, trying to figure it out, and saying, "Hmm. Guess you do it with your (hand/foot)" -- whatever is the opposite of what they personally do -- thus creating a habit set in stone. I have seen use directions on a wide variety of toilets all over the world, but I have never seen directions for flushing this kind of toilet.
I now know people put their feet up there. I doubt it will change my behavior at all. I note, FTR, that when using the kind of Asian toilet that looks like a urinal standing on its back on or in the ground, with the same kind of flusher, I do use my foot, as it makes logical sense to me to do so.
I like the large or small flush choices, built in bidets, heated seats, funny flush sounds at the press of a button, and now, the automatic seat cover and flush models. Plumbing is very interesting these days.