The layout can also be tuned for microtonal variants that wouldn't normally be playable without handcrafted custom instruments or per-string adjustable guitar frets or etc. I'm not fully familiar with the domain yet but as part of studying Caftaphata I ended up diverging into isomorphics for 41edo — someone else made https://mindparade.us/images/41edo_layout_8x8.png which could help explain that (cert warning asterisk noted).