DoQ is under heavy development, current IETF draft doq-i04 and -i03 changed wireformat and incompatible with -i02 used in Adguard DNS (IETF QUIC v1 is incompatible with Draft-QUIC-32 also). So any solution will stop work after 2-3 month. We wait for final (or at least stable) specs.
DoH + HTTP/3 is real, but only QUIC was stabilized as RFC 9000, HTTP/3 is still under review. We have no stable TLS libraries for QUIC, except GnuTLS right now. Curl's support for HTTP/3 is based on ngtcp2 + nghttp3, which has no stable releases for now also. So we wait for stable ngtcp2 for DoH+HTTP/3.