Ok, so I made a very tiny test case now that I'm finally getting around to using support (attached). I generate gcode using S3D and the BigBox Hybrid Dual setttings as a starting point. In Octoprint, the gcode looks correct in terms of printing support and the supported object. When I go to print, however, MADNESS, and not in the good 80s band way! Instead of printing the support inside the supported object, it prints another copy of the supported object in the support media to the left of the supported print. Making things EVEN MORE MAD is that the supported object is roughly ~37mm to the left, which is also the offset between T0 and T1 on my printer. What's surprising to me is that the gcode simulator is doing the right thing but the printing is wildly different. I'm running the latest version of S3D, octoprint 1.3.1, and a local build of RC6. All I changed was to enabled PID_PARAMS_PER_EXTRUDER and disable AUTO_BED_LEVELING. oh, and I changed the version number to have "jet" in it so I know I'm running my branch. Edit: my single-head prints are otherwise just fine with the exception of the printer using 190, 100 as the center of the print.