Hide upstream resolver from dns query answer

[Streametch]

Hello,
Some services, like anti spam Rbl lists, detect dns resolver public or not. If knot-resolver using forward rules to public resolvers like google/cloudflare then access to antismap RBL's may fails. Is any way how to excludes RBL's domains from forwarding, or maybe some tricks how to hide or replace upstream resolvers from query answer?

[vcunat]

In 5.x version you can use the .PASS action to skip over all further rules (including forwarding rules). So if you put this early enough and conditioned to trigger only on some QNAME subtrees, I believe it will work.

In 6.x this isn't doable in a reasonable way yet, I think.

[vcunat]

6.x: a different forwarding specification as exception should work there, so if you e.g. find a resolver that's not so well known or if you have another non-forwarding instance...