I am assuming by "fat fingers" you are pointing out the doublet scales near the end which require execution by means of hitting 2 white keys together as a doublet with certain fingers, on the way up and down, with the intent of accuracy and smoothness. This is an unusual finger disciple which I have not encountered in other works. It is not indicated as a glissando. How does a professional play it authentically? I can't help thinking that hit or miss and so it goes is the philosophy.