I remixed the original model to split into two parts so I could use the dual-extrusion wizard in Simplify3d. My first 2 attempts failed because I had auto-grouping turned on (tried to lift the top off the base and put supports in between them), and the second was because the slicer tried to create double supports for the second model (it tried to build supports for the letters which ran up through the base supports and base, which made a mess of plastic). The solution was to turn off the align and group, and to make my own supports (Tinkercad, made them 0.4mm wide and 0.1mm height below the item being supported).
Here is the process I used in Simplify3D:
Import the two models
Align them manually on the x and y axis
Start dual extrusion wizard:
Pick your material (I used ABS)
Put parts aligned with extruder/color you want to use
UNCHECK align and group
Hit OK, and then edit process settings, then I changed the following settings:
turn on raft
turn off ooze guard
I also noted that the following were defaults (which I kept):
ABS (I use 230C/110C heat settings for extruder/bed)
Ok, then print!
Here's the Tinkercad link: https://www.tinkercad.com/things/5clJPy6WEL2-flashforge-plug-dual-color-with-supports