I found a detailed post about this (lots of posts and hard to follow when you do a search) I even printed it but cant find it. Simplif圓D is a controversial 3D printing software: Some say its overpriced, others cant live without it. The measured simplified guides were compared with the CAD model, and the accuracy of the 3D printers was compared. (the gcode made my simplify 3D will include the offsets as you checked the 'apply toolhead offsets to G-code' its just that the preview in S3D does not show the offset) This will look great on the screen - if it looks OK - go back and re-check that box and then prepare to print again - it will look offset BUT print using that generated code and all will be well. If you want to see how it will actually print - uncheck 'apply toolhead offsets' in the GCODE tab of the FFF settings. Use dual extrusion wizard and when you see the preview it will show with the toolhead paths offset - this will look bad on preview but print just fine (apparently simplify 3D preview shows the raw paths NOT paths with the offset applied). A point that many have made within the 3D printing community is that, when Simplif圓D first came out, it was very far ahead of its competitors, but in recent years both Cura and PrusaSlicer have significantly narrowed the gap. It has been a couple weeks since I tried this but I think this is what works. The two most popular free software that compete with Simplify 3D are Cura and PrusaSlicer.