So the Archer C6 v4 supposedly supports DNS-over-HTTPS. 

Except… you can’t actually use your own DoH server.

The firmware only allows a tiny list of hard-coded providers. No option to add a custom endpoint.


 

Which means:

• No self-hosted DoH
   

Basically if your provider isn't on TP-Link’s little whitelist, you're out.
 

And let’s be honest — this isn’t a hardware limitation. The router already performs DoH queries. Adding a custom URL field would take one firmware update.