Thank you! I’m pretty slapdash with .internal; for instance, for a few weeks I wasn’t even copying the query record to nxdomain/noerror responses, and dig would grok them and Golang would not. If you spot more things like this, I can fix them quickly.
(Of course, if you use fdaa::3 as your system DNS server, I’m proxying requests to a real DNS server, and the handling of those should not be slapdash. It’s important not to break “real” DNS, but .internal is something less than real.)