As I am sure you know, the FC3100 does not have automated registration mark system (ARMS) built in to it, but you can still perform a flawless contour cut with the plotter, assuming that you have the proper software.
I would recommend FlexiSIGN-Pro version 7.6 or higher (including 8.x). You can contour cut, but you'll need to locate the 4 registration marks by moving the carriage over them via the control panel on the plotter. It works well, it is just not as automated as a plotter with an automated system for locating the marks.
Bob