I eat oatmeal with brewer's yeast every day, use oatmilk in my coffee for my creamer, make a smoothie with brewer's yeast, and I made lactation cookies. Power pumping had no effect on my milk supply when I tried it. I'm currently exclusively pumping while trying to get her back on the breast. Adding brewer's yeast took my total pumped milk per day from 15-18 oz to 25-27 oz. The normal amount range is 19-30 oz per day. Just know that your baby is more effective at expressing milk from your breasts than a machine.
Are you pumping in the middle of the night? That’s when your supply is the highest. If bub is going 10 hours at night without a feed, and you are not feeding/pumping either, your body is going to think it doesn’t need to make as much milk. More milk removals = more milk, so I’d suggest breastfeeding as much as possible or try pumping after feeds to ensure you’re empty. And ensure you’re super hydrated!
Probably not exactly the advice you're looking for but I stressed my self out so much trying to create a supply it damn near dried me out. I learned to just pump what I can. My husband would use that supply first then formula. When I was working sometimes I would pump enough for the day sometimes just the morning feed🤷🏽♀️
Have you tried coconut water?? I drink body armor because it has it in it. And it helps. I tried everything with my first except coconut water because I don’t like the taste. But this time I just eat oatmeal and drink body armor and I have a much bigger supply.