I actually have the same setup. UM2 with the + extrusion upgrade. I also used the original to upgrade to dual extrusion. I loaded the UltiCreatr firmware. Thus far I have been able to get it to print the first layer without issue. After the first layer the primary offsets on the y axis about 5mm toward the back, while the secondary nozzle does not. The machine also decides to goto 0,0 to wipe the nozzle and hits the clip on the front left of the UM2. I checked the gcode but could not see an issue in the commands. I was hoping to be able to convert the hex firmware code back to readable to check/update the firmware, but alas it does not look possible. I may have overlooked something. Not sure how to attach the code to the post and the limit is 20000 characters. First Pic is the bottom of first layer. The second is the top of finished print.