It's been a great little toy, I install a new firmware every couple of days. I especially enjoy the various generative firmwares.

Many of them work in browser too, which is essential for choosing what to try next!

Some faves:

NACHTFART: https://fartypants.github.io/fm1-nachtfahrt/emu/

DUB-1: https://sbegueria.github.io/fm1-dub/emu/