I could not for the life of me figure this out... until I did.
I have learned that to get S3D to do the "Additions" and Infill and supports properly across multiple tools I had to put all four extruders/tools in the Extruder list. As such it seems to work OK.
Every now and then I would get the tool change grabbing the wrong tool at the beginning of the print, it would heat up, then uncouple & drop the tool. Looking at the gcode for the file S3d had inserted commands to select and heat up the incorrect tool, BEFORE my start gcode. ??????
M104 S235 T3
M109 S235 T3
G28 ; home all axes (This is my start gcode)
; process Process1
It took me a bit to figure it out. Probably because every now and then my starting tool happened to be the last in the list...
It seems the last selected tool in the extruder list followed immediately by the user selecting OK will be inserted like this before the start gcode. AND for some REAL BONEHEADED REASON... it ALWAYS defaults to the last tool in the extruder list rather then maintaining the user selected Tool. S3D maintains the selection when switching advanced tabs, but after the user selects OK then returns to look into the processs the selection DEFAULTS to the last item in the list thereby CHANGING THE SELECTION.
You may want to FIX THIS!