Just took delivery of my brand new keychron k6, it really is a beast of a keyboard. Build quality is top of the game, everything works out of the box and to my surprise even after 3 weeks of delivery time, the keyboard was fully charged when it arrived. (which made me extraordinary happy).
I just want to address two things i stumpled upon:
Connecting multiple devices
The short manual which is part of the box does not explain how to connect multiple devices, even though i knew the keyboard has this feature. After a short ddg search, someone on reddit mentioned i should look after keys which have the bluetooth symbol printed on. On the Keychron K6 (ISO DE Edition) the q, w and e keys are labeled with the bluetooth symbol. Each of the keys are mapped to a specific device. q is now my iPad, w my iPhone and e my thinkpad. Pairing process is the same, just use the different keys for different devices.
Functioning Fn Keys
Thanks to Bastian Venthur, which had almost the same problem (he’s using a Keychron C1) i made the function keys work again. For detailed explanation check his blogpost. For historical purposes, i’ll add the code here as well.
Add the following file (as root): /etc/modprobe.d/hid_apple.conf
options hid_apple fnmode=2
reboot, now the function keys work as expected using fn2.
Bluetooth does not autoconnect
Update: 19.04.2022
Since i recently switched to cable mode and the keyboard wasnt able to connect by itself to my thinkpad, i found out i need to additionally trust the keyboard using bluetoothctl.