Btw, I've never before found a single note that I'd change regarding Chopin, but I tend to think that bar 250 would maybe even sound better if there was double B in the left hand (the first note in the bar) instead of double F# (basically a B major triad instead of T64).
It’s like saying: oh! I can play Beethoven op. 10 no. 2 pretty well, so now I can play Hammerklavier!