Here is an interesting new piece of hardware. http://www.mosaicmanufacturing.com. Could you take a look at it and integrate into Simply 3D on its release?
I was hoping that it wouldn't take a year for Simplify3d to use this piece of hardware. I have a Makergear M2 and they have a dual extruder update but it reduces your build platform. With this hardware you don't compromise your hardware. Your going to use lots more filament but up to three different filaments sounds sweet to me. There is a article on 3ders.org with conductive filament and the Mosaic.
gcodestat integrates with Simplify3D and allow you to
Calculate print time accurately (acceleration, max speed, junction deviation all taken into consideration)
Embed M117 codes into G-Code
Upload your G-Code directly to Octoprint
open source and unlicence