20+ years ago we had the same problem with one of our children. We finally did essentially the same plan. He had choice of what he could eat out of what the rest of us were eating. He could try something and spit it out with no comment or judgement from us. It was gross to eat with him but it took a year or so and I have to say that at 25 he now eats everything. He doesn’t like fish but eats it anyway, and he doesn’t really enjoy fruit but eats it because it’s healthy. Good to read your plan!