The powdered cheese that comes in your box of instant mac and cheese does a very good job of coating the noodles in salty and savory flavor. You could leave well enough alone, but a bit of over-indulgence never hurt anyone. So adding more cheese — be it cheddar, soft goat, or even blue — to the pot is more than OK. It's one of the easiest ways to build in an extra layer of flavor to your standard box of instant mac and cheese.
Add More Cheese to Your Boxed Mac and Cheese — 10 Ways to Upgrade Mac & Cheese