To answer my own question, I am switching back to the single extruder tool head for single material prints.
The .6mm nozzle on the Flexy Dually isn’t giving me the same detail as the .5mm nozzle on the single extruder.
I don’t see any logical problem that requires the two nozzles to be the same size. It only prints with one extruder at a time, and only one layer at a time. Is it just a software limitation with Cura?
Doesn’t look like Simplify 3D has the same problem as Cura. In Cura in dual extruder mode, you basically can only set the temperatures different for each extruder. Everything else has to be the same.
It looks like in Simplify3D you can set up each extruder separately, which will allow it to run significantly different g-code for each.
I wonder if you can replace the .6mm nozzle for the rear extruder with a .5mm nozzle and then use Simplify3D to get the same quality printing out of the rear extruder as with the single extruder tool head?