Low tech options: a smart plug that power cycles if it can’t ping eg google and have your edge devices plugged in there, or a timer that reboots the firewall at 0200 daily.

I have decided dual firewalls are silly without dual internet and dual power, as both those things go down more often than my FW.

I have two instances of pihole on two hosts, because I block dns outbound to the best of my ability.