Just curious as to what folks have been doing and what's needed.  I have a 32GB sd card that I use as the main card.  It also contains the firmware.  If I have a spare 16GB card, do I need to have the latest firmware on that card as well?  Wasn't sure if it was going to re-update or downgrade the firmware if I use another in the event a card gets full.

I see no reason to have firmware on your memory card, unless you're going out and buying new batteries every month or so.  It is used once to update the components and not needed again on that equipment.