Was rather shocked to find BT hubs don't allow you to change DNS servers anymore and force you to use their own ones, so I can't properly setup adguard.
What routers are people using now that are reliable and will let me control my own network configuration
Old computer, or Raspberry pi with proxmox and pfsense on it. The positive thing is that you can run other servers as well (pi-hole for example for network wide blocking ads)
If you're using pfSense anyway, pfBlockerNG provides the same AD related DNS sinkhole functionality of pi-hole without the need for a whole separate machine/VM to manage.