I'm not a vegan (actually, not fully a vegetarian either, but that is not a matter for this board, except for the desire to cut down on animal-based products) and have a terrible time digesting most legumes. I can usually handle lentils (which I love) and very well cooked white beans, as in soups or stews. I love black beans, but they don't always love me. And yes, of course I've tried Beano.
One thing I'm wondering is if edamame are easier to digest than riper, dried soya beans.
When in Amsterdam, I was pleased to have had no digestive upset eating fermented tempeh. It is hard to find in many places, except for ludicrously expensive and overflavoured versions in some healthfood stores. The quest for plain Indonesian tempeh (yum) continues.