Glad to see things are still cooking on the ultimate DIY DTG. Just a thought. If the platen bed is aligned manually with an alignment mark as yours currently does I would think not much problem in backlash, as long as the same method of setting the mark, i.e. the tension on the bed is the same when set. However if sensors are used and the bed would auto set itself and then auto reset for second pass I can see a backlash error happening. I have a TJet 3 in pieces now, just for the heck of it. It uses a screw drive but seems to have registration problems. I am convinced that a great deal of these problems are due to incorrect setting, adjustment of the backlash nut on the drive. I know yours (German 13) is a manual reset which I have on my DIY and it is very accurate. Just a thought.