OK David - I'm assuming you have only a Single Head printer - and thus you can NOT do the famous Full Contact Support via 2 print heads or an AMS. Am I right???
During my time at Essentium - we were working on something called an Easy-Rip-Raft. My coworker, a REALLY Smart dude - he was working on a Technique - where essentially the Top of the Raft - and the Bottom of the Model - were VERY Different Temps. I suspect it was the Top of the Raft is printed at the LOWEST temp you can print the material - without a Filament Jam in the Nozzle. Then - the Bottom of the Model - which touches the Raft - it would be Hot - and thus the Normal print Temp - maybe Bottom of model is printed Hotter than you would normally print - and the rest of the layers going upwards printed at the Normal temp. Since - tests proved that the Temp Differential allowed the Raft to Easily remove from the Model!
So - there you have it - in a Nutshell...
And - as I was JUST Thinking about this - might be Interesting to experiment with this concept for a Full Contact Support - but, Support & Model of Same material. OBVIOUSLY - this would ONLY be Viable for a Fully Horizontal top support layer - NOT viable for Angles or Curves - so VERY Limited Usage case!
-K