How do I set the MTR to provide a specific DNS rather than the mobile provider's DNS or LAN DNS?

RESOLUTION: Upgrade to MTR firmware 4.0.5 or newer, disable "Enable Forwarding Server" and enter the desired DNS IP addresses (different from what is shown for WAN DNS Servers from the mobile network provider). For example, enter 8.8.8.8 and 4.4.4.4 for the DNS servers. Now Save and Restart. The DHCP clients now get the 8.8.8.8 and 4.4.4.4 assigned instead of the LAN IP address for the MTR as DNS. If you continue to get a DNS that is the same as the LAN IP, then the MTR is acting as a DNS Proxy.