Hello and welcome to the forum. We have quite a bit of information about pancreatitis on the forum. If you use the search box at the top you will be able to locate each thread that contains the word 'pancreatitis'. Here are some threads:The pancreatitis thread.Diet for pancreatitis.
David has written this information
about prescription diets. He has also written a page on feeding dogs with pancreatitis here.
The Royal Canin GI low fat dry food information is here.
It has 7% fat, which is very low. There are very few commercially available foods that have a fat level as low as that. Usually low fat foods are categorized under 'light' 'senior' or 'diet' labels. They are not often recommended for long term use because dogs need fat in their diet. They can be found by using the filters on the Dog Food Directory.
As you are working with your vet on this issue, I feel that the best approach would be to discuss the specifics of the food, e.g. the percentage of fat and protein. This will then enable you to search for something better (and cheaper) than the Royal Canin. All of the low fat foods will contain a high percentage of carbohydrate - this is unavoidable.
As your dog is very young and has not had a flare up for 6 months, I can't see why you should not look for a new, digestible food that has a little more fat in it. However, as you are under veterinary care, please speak to him or her about any changes. Any reputable company should be able to give you full information about their products but I am not sure whether they would categorically state that it is formulated for pancreatitis. I can't remember now but there may be legal issues regarding this. Re the insurance company, if you have ascertained key features of a suitable product from the veterinary surgeon and had agreement from him that your chosen food would be suitable then surely that should satisfy them.
It might be worth looking at the cold pressed foods
because they are usually low in fat and very digestible. There are a few UK companies who sell them - their customer services should be able to help you with information. Gentle might be a good place to start. They have a fish variety that might suit quite well.
I would be grateful if you would update your thread because we really need feedback. It helps other people (and us) enormously.