Thanks for the clearing our misunderstanding up.

It looks like the DueX2 method will work for us. However, I'd certainly be interested in the hybrid boards if another run was on the near horizon.

I'm planning out upgrading my printers electronics to the Duet Wifi and ran into some I/O slot questions. My machine is a rather large one with 4 each of extruders, heaters, thermistors, fans, and relays for pneumatics. The XY gantry system is made up of a couple 6.3A NEMA 34's with 3.0A NEMA 23's running the Z, all from external drivers. As a result of using external motor drivers and needing quite a few extra I/O connections I'm looking at utilizing the DueX5 extension board.

My Question: Can I "hack" the 50 pin ribbon cable running from the Duet Wifi to the DueX5 by diverting the Step/Dir/Enable pins for each of the 5 drivers while still maintaining the integrity of the extra connections of the DueX5?

I found this thread that discusses a similar question, however I wanted to verify that this is possible for my specific case.
https://www.duet3d.com/forum/thread.php?id=1302