The issue with the spring loaded filament motor is that it presses the filament too tightly, teeth cut in, and can pull it out of the head (that's what she said). Another thing is the hydraulic pressure that builds up on extrusion when you load the filament, if it enters head it heats too slowly and a lot of pressure builds up that's enough to curl the filament past motor and before head (due to slow heat transmission). You got to preheat the filament in the head before moving the motors.

Put the filament into the motor by hand, as far as you can, with preheated head. Ideally you want it to extrude a bit while pushing by hand. Then pull up a little. It should print OK then. If not, loosen the pressure on the motor lever (place a toothpick in it or sth).

Geoff, as I said in another thread, good luck with the build.
I'm kind of worried about Flashforge that they have a good product that works fine, and instead of honing it into perfection they release new revamped better bigger harder versions. It's kind of stupid imvho, and I worry they will try to abandon the working Rep1 based design in favor of the other nice shiny glossy ones like MB and a lot of other companies did.

I wish they'd go the route to perfect the existing wooden design so you could buy those printers even more cheaply, run them down to death, then get more.