There has been some activity in this area, you can find threads scattered all over the forums, but not many. I believe @Tom_A cut 3/4" acrylic, @rpegg cut through .4" oak with a pre-release unit that had a Pro tube in it and there has been some other activity. I believe Tom used multiple passes, lots of passes, and rpegg did it in one or two. It depends a lot on the material being cut. There are some caveats. Organic materials (basically wood) accumulate a lot of char, while plastics (basically acrylic) can get a lot of melting along the edge. The edge is not going to be very perpendicular; if you don’t want an oddly sloping edge there will be some sanding involved. So go ahead and lead the way on doing this successfully.
IIRC glowforge has dropped claims of automatic flipping and cutting. At any rate it is definitely not in the current release of software. That doesn’t mean you couldn’t make a jig. I believe there is a good jig making tutorial in the Tips and Tricks section of the forum.