DNS server suggestion: include DNS server address also by IP address

I am on Android 9 and have DNS-over-TLS Private DNS enabled. When I connect to a network that blocks port 853, Android reports that the WLAN has no connectivity, but when I use Intra using a direct IP address, everything works (regardless of the error).

If I understand correctly, Nebulo works similarly to Intra and initially resolves e.g. dns.quad9.net using the private DNS server which being blocked fails, so there is no connectivity. As some of the DNS servers have valid certificates for IP address, my suggestion would be having entries like:

• Quad9 DNS (by IP address): main address: https://9.9.9.9/dns-query, secondary address https://149.112.112.112/dns-query
• Cloudflare DNS (by IP address): main address: https://1.1.1.1/dns-query, secondary address https://1.0.0.1/dns-query

It would be even better if four addresses were allowed as currently it's not possible to have both IPv4 and IPv6 addresses enabled, unless the main resolver is IPv4 and secondary IPv6 or vice versa.