Hello and welcome to the forum Ruby 2020. I have friends who are experienced Labrador owners and I understand that this is a common problem with the breed. One of them currently has a Lab with the same issues.
I have a dog (not a Lab) with skin problems and malassezia so I know how difficult it is to find a solution. I eventually took her to see a specialist which was enormously helpful and the dog has been in remission for some time. We automatically blame food but it could be something else, environmental or genetic. The difficulty is discovering what is causing the problem and how best to ameliorate it.
Prior to seeing the specialist the vet put my dog on one of these hypoallergenic diets and it made no difference whatsoever, despite a lengthy trial of almost three months. Like you, I was reluctant but I thought it was worth a try. It can be a useful to try an elimination diet with veterinary support. As you say, they are not particularly wholesome but they can be helpful in the short term. You have to make your own mind up about it. Sometimes owners have an idea what the dog cannot tolerate. In my dog's case I suspect legumes and white potato. Dr Karen Becker
recommends a low carbohydrate diet. You suggested two products, both dry but the problem with many dry foods is that they are usually high in carbohydrate. There are a few high quality ones that are in the low/average bracket.
When my dog had malassezia she also (latterly) got it in her ears but I was able to clear it up quickly because I had already cleared it on her body. I had to bath her using Malaseb and the treatment was very intensive for quite a while. Diet wise, I changed her onto fresh cooked food which the dermatologist had approved. It contains many good vegetables, is low/average carbohydrate and has turmeric in it. I stick with just a few flavours which I know she tolerates.
I think it's a good idea to make the diet as simple as possible and to know exactly what it contains. If you are able to cook for your dog it might be worth a try. My dermatologist gave me a handout and this is what she advises, starting with very limited ingredients. This has to be done properly and we have some useful links in the home cooking section. I buy a commercially prepared fresh cooked food but it can be expensive for large dogs. A good quality raw complete could be worth considering because they tend to have a high fat content but low carbohydrate.
If your vet can do a skin scraping he or she might be able to identify if your dog has excess yeast elsewhere in the body and if this is the case it needs to be treated. Dogs scratch and reinfect themselves. Regular washing of feet might be worth considering. Some people use dilute Hibiscrub for the purpose.