I had this response from Lisa in April...........
Hello Beverley,Converting out of AccuMark in mm is still under construction, so for now, if you convert out of AccuMark it will still be in cm. Keep a look out for information on future releases. You can check back on the status of the item which has a reference number of APDS-5914, use this number when inquiring on this feature. Thank you for using Gerber Community.
I've already set the P user Environment to mm but any piece data doesn't EXPORT in mm, it only EXPORTS in CM and I don't get the option to change this in DCU.
I've read the documents and see nothing in there that will help unless I'm missing something?
I open the files up in AutoCAD and Cutworks and they are both in CM regardless of the User Environment set for mm.
Lisa, that's brilliant thank you.
Would very much welcome this.