Despite the end result being the death of everything within a single lifespan and the eventual destruction of the entire Earth in the new term future, I was surprised it would not be more immediately destructive. 1 cm/s sure sounded like a pretty fast expansion.

Actually, even if the density was constant, the earth would turn into a black hole when it reached about 1.925 * 10^13 times its original mass, since the mass of a black hole is proportional to its radius, whereas the mass of the earth in this scenario grows proportional to radius cubed. This should happen around 371 years (?) after starting.

(Please check my calculations, I’m not 100% sure.)