At the moment, the best hot-swappable keyboard I've tested is the Glorious GMMK 3 - it's easily the most customizable way to build your own custom keyboard without diving into the expensive parts ...

Harmony as Flags 🇱🇺🇱🇹🇬🇦🇦🇲🇲🇺 Western scores in 12 colors. MIDI files in, piano rolls out. Abolition of standard notation's gatekeeping. Prosthesis for sheet-music-blind people. Syntax ...