I use it on a linux system with "the switch" in Mac mode. The switch setting hardly matters. See notes on "layers" below.
To get fn keys (F1 to F12) use the fn2 key and the corresponding number. So, to get F7, use fn2 and 7. Beyond F10 (obtained using fn2 and 0) imagine that things just continue along to the right. In other words, to get F12 use fn2 and the = key.
Adventures in Computing / tom@mmto.org