This is fascinating! I’ve never played a YC seriously, but I have played several Yamahas and currently play on a Kawai and Baldwin. I’ve often wondered if the Baldwin or Yamaha is laid out slightly differently than the Kawai because I feel like playing broken 4 note chords the fingering can feel off on one piano vs another. It’s a slight stretch but the 4-5 on the second 4 note chord can be uncomfortable on the Kawai and comfortable on the Yamaha. I never play them in the same room, one is at my teachers and one at home.

Very interesting! Is there a spec for this? Or a layout description? Surely something as precise as piano would note this.