From Vagabonds in Anacortes, WA.
Canadian poutine eater here… IMO sadly there is no substitute for the curds. They are just texturally unique. It’s quite important considering it’s one of only three ingredients.
I know your pain though, I was living in the states for a bit and it was basically impossible to get good poutine. If I wanted it I had to make it myself, which meant a long trip to Tillamook to buy cheese curds from the source direct.