This is interesting, something I wasn't aware of. So, if you are sitting at your computer and the printer is in the other room you can advance the paper a few inches and cut it off with the auto cutter and then start printing? Do you leave the roll paper in your 7900 all the time? I had intended on using the barcode.
I believe you have to be at the printer to advance/cut. Easy to do, press a couple of buttons. If you need to do this from another room, you certainly could send a "dummy" file a few inches long. I move between sheets and rolls quite a bit, and I do use the barcode to track remaining paper length. However, I have left paper in for more than a day, such as Hahnemuhle FAB and not seen a problem.