I was having this same issue and your fix did exactly what I needed. If I had a part on the 0 side and wanted to machine on the 270 side, it would post A270. But, if my part was too big to go all the way around, I would have to manually edit the A270. to A-90. With this edit to the post, I now get -A90. for the 270 side, and A90. for the 90 side. Thanks!