I read somewhere that the BCM43438 identifies itself as the BCM43430 so maybe that firmware/driver will work for it for Kernel 4.1+
[edit] Possible it uses the same Wifi as the Chuwi Hi8? This page says the Hi8 uses the BCM43430.
It’s not very encouraging. I might be better off with the Hibook Pro or Cube iwork 10 that use the Realtek RTL8723BS WiFi. At least there seems to be more development work going on there.