personally, i don't really mind if the art style must be entirely revamped for the sake of congruency. i've seen that happen before. i do, however, think that nanoff's legacy should remain somewhere in game. either as accessible rewards from fulfilling achievements or maybe a speedrunner route exclusive alternate art. it's supposed to be a joke route anyway, we could write off lacking pieces of art nanoff couldn't get to required for the rest of the game as saving frames or skips.
maybe not the best solution, but just to throw some ideas around. any approach to this is going to offer it's own set of challenges.