I just printed one of these with red ABS and it came out great! Two opposing gears had to be "pushed" as they were locked into the outside, but they came away clean with a little "snick!" I'm switching from the blue-tape to a borosilicate glass bed over the next few days, so we'll see how that works. I haven't tried PLA yet, as I'm just learning (this is my third print on the FlashForge Creative Pro) but soon!
Would it be challenging to print the the outside and center with a different filament using dual extrusion? I have SImplify3D, but I'm not sure if I'd need to open it up into something else first? FreeCAD?