Thought I would revisit this thread after a near expensive mishap that occurred today. I had sent about 16 tonnes of chequerplates to customer for cutting, most were odd shapes and all were modeled in the same plane, some were folded plates so I was not able to use the variable grating for chequerplates which shows a top side, so I went with regular plates. I created drawings and all were correct and matched the clients design. However, the DXF files created were in the majority of cases upside down. Now on a normal plate that doesn't matter and I have done 10's of thousands of plates, but with chequerplates this is a big problem, (see attached screenshot)

As you can see the DXF was created from the underside, and this was repeated on many other plates, I wasn't concerned about rectangular plates but only the irregular ones.
Fortunately the machine operator picked it up before running and stopped the process, once informed I manually mirrored all the problem DXF files and sent back and all is well.
Like most people we don't double check our DXF files we assume they are correct and they are. This is a warning to anyone who uses any coated material, stainless steel polished sheets, Alpolic or composite sheets or chequerplate, or even painted and unpainted surfaces that you don't want the numbering to view as identical that requires folding or not to be very careful.
I have updated the Ideas station https://forums.autodesk.com/t5/advance-steel-ideas/additional-surface-side-property-of-plates-needed... (thanks Christian Blei) and the addition of a switch to set the top of a plate would be very, very handy.
Gary