My friend and I have started to deliberately grind balloons because we were worried we'd miss several recipes otherwise. As of today we're both only missing two.
I think I've only gotten two mushroom recipes, and one of them is the one that Isabelle gave me at the start of autumn. I shot down a mushroom recipe from a balloon and it was a duplicate of the one she gave me. They're so rare! I've been collecting all the mushrooms every day for nothing because I have no recipes to make anything. I really want the mushroom lamp recipe.