Recently went down a little rabbit hole to get my house in order when I noticed weird things showing up at https://dnscheck.tools/ . (I don't really understand how these checks work though)
It shows that my DNS resolvers are my (public edge) gateway server and then declares that the DNS resolver belongs to my ISP although the PTR is correctly (more or less, let's not get into it) set to an FQDN which is under my domain. In actuality my resolvers don't have public addresses at all (and all of the DNS traffic does of course go out through the gateway server).
[–] m3047 2 days ago