As I mention in the post, I make my own Roasted Mushroom Stock. When I don't have any, I use Pacific Foods Organic Mushroom Broth. It's very flavorful. Starting with the broth hot means the IP/PC doesn't have to get it hot thus saving quite a bit of time! Drop the kombu in with the broth to start the flavor infusion (if using).
Not all miso is gluten free. Check the label. I typically keep shiro (white) miso in my refrigerator, and that is what I have used here. The darker miso is used with meats (IMHO).
I am reluctant to use or suggest specific settings for the IP/pressure cooker mostly due to the fact that there are many brands and many settings. Additionally, different beans need different amounts of time, and the appliance doesn't know what kind of bean you're cooking. Older IPs have a "manual" setting, and newer ones have a "pressure cook" setting. My Pressure Cooker XL has a "beans" setting that can be adjusted. I do adzuki beans for 15 minutes, with a quick natural release (10 minutes and then release pressure). I'm happy with that texture and firmness.
If you're cooking on the stove, after pre-soaking, the beans will require about 45 minutes on simmer. See Cooking with Adzuki Beans for more information.
I do want to mention that altitude probably will affect cooking time. I live at sea level, and with my pot and my altitude 15 minutes is great. Make sure you check that the beans are very close to being done before removing them from the pressure cooker prior to making the soup. If they're more than slightly undercooked, lock the lid, and add a few minutes.
This is a good article on IP buttons from my friend Barbara at Pressure Cooking Today.
Macronutrients (approximation from MyFitnessPal.com): 265 calories; 16 g protein; 7 g fat; 36 g carbohydrates. Does not include garnishes.