

Unattended-upgrade does security-only patching once every 4 hours (in rough sync with my local mirror)
Full upgrades are done weekly, accompanied by a reboot
I find that the split between security patching and feature/bug patching maintains a healthy balance knowing when something is likely to break but never being behind on the latest cve.



CGNAT does have a designated range by spec. 100.64.0.0/10, which covers addresses from 100.64.0.0 to 100.127.255.255. Technically they could be using any other private address space but it would be very uncommon in a modern ISP.