Would you provide your physical home router to me for an “audit”? I promise not to do anything with it and you can be assured you can continue using it afterwards with no worries about your security.
I imagine Maricopa county has no interest in throwing away all these routers and buying new ones. This is on top of the disruption of service that providing the physical routers will cause.
The whole letter is worth a read by the way:
https://www.maricopa.gov/DocumentCenter/View/70435/Final-Sig...