Both palm keys together to trigger a separate layer?

[andrewg (Andrew Gallagher)]

@algernon

One way to do this would be to put the third layer after FUNCTION, but before NUMPAD, and turn both palm keys into Key_KeymapNext_Momentary. This way when you press one of the Fn keys, you get to the FUNCTION layer. If you keep holding it, and press the other, as that key now goes to the next layer instead of a specific one, you’ll end up on the layer after FUNCTION.

This is a great tool, but it comes with a big caveat. You MUST define at least two layers above the last lockable layer (usually NUMPAD) - otherwise once you lock into that layer you can overflow the layer array on read by pressing the function key(s) - which then returns scancodes derived from uninitialised memory…