you can upgrade an Apple Silicon Macbook Pro's SSD. These guys will do it for you. but if you're going from 128/256/512gb to 1/2tb, they also have to replace the T2 security chip, so Touch ID will never work again
yeah we can get your SSD past a terabyte, but you're going to have to stick your hands on this orb from Men in Black. no it won't hurt at all I promise.