Thanks to +Ricardo Salveti for lots of help getting this working. It took me about 12 hours from start to finish (not including repo sync time). I have never used CyanogenMod or built an Android ROM before, so I think this is pretty good, and it says a lot about what can be done when using Android effectively like a HAL - without having to actually know or care anything about Android.
The porting process was really simple once I understood what I was doing. The phablet system is a cut-down Android with Dalvik etc removed, and the hardware adaptations we are bringing over from CyanogenMod try to build Dalvik runtime applications. This stuff has to be stripped out from the HW adaptations. That's really all I had to do to get this working, and if you look at my repos above you'll see that all I did was comment out lines in Makefiles which try to build this type of stuff. There were a couple of other trivial changes needed too. All in all only about 20 lines changed.