Alternative to RC hypoallergenic

Hello, I have a nearly 9 year old German Wirehaired Pointer (weighs between 35-40kg depending on the time of year) who over the last couple of years developed skin, ear and digestive problems that were suggested by the vet to be allergy related. He also has occasional (about once per year/18 months) movement disorder episodes which have been occurring since he was around 5 years old. After many many months of antibiotics, apoquel, medicated shampoos, diet trials and feeding royal canine hypoallergenic food, he has now settled and been weaned of all medications with no reoccurrence of his skin issues (turned out to be a resistant bacterial infection and completely cleared up on special antibiotics so I don’t believe was linked to “allergies” in the first place). He has always had a sensitive stomach, particularly bad with fish based foods and I have also linked the “movement disorder episodes” potentially to rosemary extract in supplements/food. He also recently had struvites in his urine which I believe can sometimes be an issue caused by the nutritional balance in their food.

My concern is, particularly as he is getting older, that the royal canine hypoallergenic food is not the most nutritious food I could be feeding him, especially for the price! I would like to try switching him to something that will still work with all his sensitivities, but will also give him the best nutrition as he ages. He was fed raw from a puppy up until his “allergies” started a few years ago, I don’t really want to go back to that as his tummy seems much more settled on kibble and we also travel a lot in our campervan so raw food is not very practical for us anymore.

Any suggestions of a better high quality “hypoallergenic” or sensitive tummy alternative to his current food would be much appreciated!

Thanks!