Miyoko Kobayashi-sensei mentioned that she might release a composer breakdown for the compositions not included on the soundtrack. Let's make this a little easier to track:
Edit: Please note that some of the titles for compositions not included on the OST (given in the leftmost column) are
tentative titles thought up by the composers and may change if there is a full soundtrack release. It's probably best to stay close to the Japanese for this list but official English titles should stray further to get closer to what was meant.