[...] > iwn0: could not configure bluetooth coexistence [...] > > What does "coexistence" mean? Presumably this is different to attaching > a bluetooth driver to the same device? (Shame Intel don't provide > documentation for the WifiLinks AFAICT...)
It does not provide Bluetooth; it provides the option to interfere less with Bluetooth. 802.11's channels are on 2.4GHz, the same as Bluetooth.
