I've been away from KSP for a while, and noticed a news post about Steam Controller support. I tried loading up KSP on my Macbook, but whether I open it through Big Picture or the regular desktop Steam launcher, I cannot seem to get KSP to go into "Steam Controller mode". The Steamworks plugin is present in my plugins directory, and the controller is plugged in and light up (and working with the default "desktop" mappings).
Is there some trick to this, or does it simply not work on OSX?