I don’t know about the plans, but I have my own version with various fixes and improvements…
http://ffauploads.com/picocalc_keyboard.ino.bin
differences from stock shipped firmware:
- ability to read backlight of screen and keyboard
- ability to read battery %
- allows setting backlight of keyboard
- other bugfixes from current firmware related to i2c and such
differences from both stock and current firmware:
- improved backlight curves (in my opinion) for display and keyboard
- ability to read battery % sooner after boot (2 seconds instead of 20)