[noob] num layer for the bluetooth/bootloader keys

[enoryw]

Disclaimer: new to ZMK, this is my first config.

So it seems pressing FN layer and smart num (layer) key accesses the symbol layer for the the bluetooth/bootloader keys.

This binding to access the symbol layer also triggers toggling sound on/off--isn't that a bad idea? E.g. sound shouldn't be messed with when bluetooth or flashing firmware is involved.

[urob]

This one is indeed a bit tricky :)

The SYS layer is activated when both the FN and NUM layers are simultaneously active. The tricky bit is that the FN layer doesn't have a way to activate the NUM layer (the corresponding key is overwritten with C_MUTE). Hence, one must first activate NUM and then FN.

TL,DR: Order matters. (1) activate NUM, (2) activate FN, (3) press &bootloader.

I should probably document that somewhere.