Prepare the pasta according to packaging instructions. Rinse with cold water and set aside until ready to use.
Preheat oven to 350°F.
In a large sauce pan, add the butter and melt over medium heat. Once fully melted, sprinkle the tapioca starch or flour over the melted butter and, with a rubber spatula, mix until fully combined. Continue to mix to prevent it from burning to the bottom. Cook for approximately 1 minute, until a film begins to form on the bottom of the pot.
Reduce heat to medium-low and add the milk into the butter mixture, whisking immediately. Bring the mixture to a slow simmer while continuously whisking to prevent lumps. Once it comes to a simmer, the mixture should begin to thicken. Add in the cream cheese and continue to whisk until fully melted and incorporated.
Combine the remaining cheeses in a bowl and add about ¾ of the cheese into the pot. Whisk until melted. Remove the pot from the heat and add in the cooked pasta, chicken, buffalo wing sauce and salt and toss to coat. Feel free to adjust the amount of buffalo wing sauce to taste (more for a spicier version, a little less for a milder version).
Pour the mac and cheese into an oven safe baking dish. Sprinkle the remaining cheese across the top and bake for 25-30 minutes, until the sides begin to bubble and the cheese on top has melted and browned slightly.
Remove from oven and allow to cool slightly before serving.