Yeah I also have/had a lot of dermatitis as well as EC and I don't think they are separate issues. i think they have the same cause.
Sun helps me too. I also use an anti-dandruff shampoo but I think we should both accept that using a product to disguise the dandruff is not solving it, only masking it.
Focusing on killing yeast or strategies to kill yeast should not need to factor into your thinking process, it should be something your body keeps under control without you thinking about it. Aim to get to the point where these problems are resolved without having to micromanage them, this is what I'm doing.