I had a cat who fully blocked on BB. He was on Royal Canin for a while, now just gets regular canned with a tablespoon or two of water added. He has never had crystals since (knock on wood, of course).
IMO, based on extensive research, dry food is the worst thing you can feed a cat. Any dry food. And after having one rushed to the e-vet and surgery for a blockage and another developing diabetes, which required daily blood tests and insulin injections, I will never feed another cat dry food again. Unlike dogs (which can certainly also have issues), cats are obligate carnivores and are designed to eat a very low-carb diet. Like less than 7% of total calories from carbs-far less than any dry food can deliver. Since switching to an all-wet diet, my cats (ranging in age from 7 to 15) are in better weight, have shinier coats, and are more active than they were on any dry kibble.
Here is a well-written website, by a veterinarian who specializes in feline nutrition. It’s a good read, easy to follow and addresses cats who have had crystals and/or blockages. It’s definitely worth checking out.