CloudFlare:WARP VPN:Status

You can detect a WARP connection vs a DOH connection by parsing the output of https://connectivity.cloudflareclient.com/cdn-cgi/trace from the host in-question.

You can frequently discern between a DOH or WARP configuration by checking interface names mentioning Cloudflare% for Linux or Windows.

WARP connections will show as a p2p VPN link. DOH instances will contain a DNS anmeserver on the 127.0 network