I'll probably get around to adding mention of the Renew Only filter in the guide by some time tomorrow night.
I would also mention the Renew All option but I found an issue with it. When using Renew All it will add cancelled rentals to the list of cards to renew, and charge you the cost to renew those cancelled rentals. I'm assuming the DEC/credits taken this way for cancelled rentals are simply being added to escrow and will be returned when the cancelled rentals expire. Perhaps Renew All could be updated to exclude cancelled rentals.