I have thought about that, the issue is I’d need to re-run all but 1 of my Ethernet cables to a place where I can put the Celeron box. Once I start messing around with VLANs this is probably what I’ll do, but it’s going to be a big project.
I’m definitely going to give Adguard Home a shot.
Any thoughts on the best solution for now, basically putting the firewall in between the router and modem? If I plug it into a LAN port on the router and set up DHCP so it is the new gateway, that should work, right? I really wish I could plug it into the WAN port but I don’t think DHCP will traverse the WAN to LAN ports on the router.