I think I found the answer to this. It is part of CutList Bridge. If you don’t check “Cabinet/Resize Mode” (which I wouldn’t for CNC’ed panels) the “Swap L/W” checkbox remains.
According to Joe’s Cutlist Bridge Documentation:
“Swap L/W – The user can specify in SketchUp any component whose length and width should be swapped. CutList Plus fx assumes the length field specifies the grain direction. However, there are times when the short dimension of a board should be the grain direction. Check Swap L/W to accomplish this.”
I haven’t actually tried it out yet, but I’m assuming Joe is using Cutlist fx’s DXF export functions, which would pick up this setting and rotate the part.
So, I think I found the answer, in the companion software. I’ll give it a try soon and let you know if it works as hoped.