One thing to consider is how appropriate a device that has RAM measured in handfuls of MB and a flash file system that isn't intended for more than a few thousand write cycles is for spooling and rasterization of print jobs.
An A4 / Letter page is on the order of 35 million pixels at 600 ppi.
The question, at least for me, becomes moot when you consider that a Raspberry Pi Zero W is US $10 and its microSD card can be swapped out when it fails. Not that the Zero W is the best option, but that there are plenty of options other than router hardware running an OS tailored for routing.