PCB designer of the board here - The second switch can toggle USB/Bluetooth profile 1/Bluetooth profile 2 (3 pos slider), but the board runs the open source ZMK firmware and you can reconfigure it however you want. Auto-switching between BT and USB is not used on the current firmware (as it would make the USB slider pos quite useless), but the firmware can absolutely do it.
EDIT: You could for example reconfigure the slider to switch between BT profile 1/2/3, and have the board auto-switch to USB when plugged in. Would take ~2min for me since I know my way around ZMK, bit more if you have to dig into how ZMK works first ofc.
Congrats on the design, using ZMK seems like a solid choice.
Did you consider adding a small screen?
I've always hated bluetooth keyboards until I built a Zaphod (which also runs ZMK). And just being able to see battery estimate, whether it is trying to pair, or which device it is currently connected to has made it a much smoother experience.
Sure thing. We'll release the original firmware configuration alongside with the board, so changing the keymap and recompiling a new firmware wouldn't be a big deal, flashing is easy over USB (and once ZMK studio is ready, you will even be able to live-remap over USB/BT without a recompile/reflash).
EDIT: You could for example reconfigure the slider to switch between BT profile 1/2/3, and have the board auto-switch to USB when plugged in. Would take ~2min for me since I know my way around ZMK, bit more if you have to dig into how ZMK works first ofc.