Not that I have noticed. I dont think backlash should be an issue since you only drive in one direction, your retract might be a bit sloppy but you should end up in the same place when you go forward again.
One issue with the design at present is that there is no adjustment on the gears (the motor has some, but the secondary drive gear has none). The gears are modelled to mesh at that distance, but your backlash depends on how accurately you can print them. They came off my printer about 0.5mm oversize which meant they have very little backlash but were quite tight when I first assembled it. I was missing steps on some tight spots for a little while till they wore in a bit and sorted themselves out.