I also am a fan of nutritional yeast.
Here is an article I always refer back to
Niacin Deficiency in Waterfowl
With angel wing, I noticed it with two of my Call Ducklings right as their large wing feathers started to come in. I really did not want to wrap them and found some folks that mentioned they had success with holding their ducklings wings in correct placement for about 30 minutes a day and everything resolved within a short amount of time. With my ducklings, it corrected itself without issue. Their flockmates were nibbling their wing tips because they stuck out and I don't know if that encouraged them to work on the muscles to be able to tuck them properly or if it just happened as they adjusted to the new weight of the feathers. It's really a toss up but I was really hoping to avoid wrapping and luckily I did.