No opinion on AdGuard, but there are several options for ad blocking DoH:
- https://ahadns.com/
- https://blahdns.com/
- https://controld.com/free-dns
- https://libredns.gr/
- https://mullvad.net/en/help/dns-over-https-and-dns-over-tls/
- https://rethinkdns.com/
There is Batsh, a simple language with c-style syntax that compiles to bash and batch.