I have no experience with repetier firmware at this time. Sorry. But unless you set the retaction distance and filament diameter in the firmware it is not on. Some people use 1.75 some use 3mm. Im not sure that those can be set from the gcode, maybe, like i said i have never used either. Im very happy with how my printers print and don’t thi k any extra tweaking would make a substantial difference to my print quality at this point.