>
The code LM(3,MOD_LALT) will momentarily switch to Layer 3 with LALT activated.   
With that in mind, here are two questions:

What key on Layer 0 is this LM(3,MOD_LALT) functionality mapped to?
On your Layer 3, what is the number 4 key mapped to? >

Ah i just found out that wireless pcbs doesn't support the LM command, i was using it just fine on my Fairbanks (Ikki68 R1 Wired PCB) but it doesn't work on Iceland (Ikki68 R2 Wireless PCB) and my friend's Finalkey V65 Bluetooth PCB