adding handshake as an alternative DNS service. This will allow decentralized peer-to-peer root DNS.
How do you propose this be done?
Note that the DNS service you want added is " An experimental peer-to-peer root DNS".
"Its purpose is not to replace the DNS protocol, but to replace the root zone file and the root servers with a public commons."
Pi-Hole does not communicate directly with the root servers - it communicates wtih DNS resolvers, which in turn communicate with the root and authoritative name servers.
I've tested an upstream dns over pi-hole that supports handshake domains and it seems pi-hole doesn't seems to work, it returns:
Jul 27 16:56:42 dnsmasq[1256]: query[A] proofofconcept from 127.0.0.1
Jul 27 16:56:42 dnsmasq[1256]: config proofofconcept is NODATA-IPv4
So this is user-defined and expected behavior. You configured your Pi-hole to not forward non-FQDN. It is meaningful as most of the time, the upstream doesn't know how to reply to queries like raspberrypi
However, sometimes this is indeed wanted and Pi-hole offers this possibility easily accessible through it's settings page.