At this point, Huff & Trickett have to start the QB who they feel will give them the best chance to win. The reason is that 6th victory, which at this point, is gonna be challenging to obtain.
I think we all pretty much believe that Cam's ceiling as a QB is pretty low, but making the bowl game is a pretty big deal for a few reasons even if the bowl looks pretty crappy to the outside world. So playing another QB primarily for the future instead of winning this season will be off the table.