First tries with DNSSEC on subzones: no success / 2019-12-24

I tried adding subzones with DNSSEC by adding the DS record to the parent zone, but in both tries I got errors from DNSViz. Different errors even: in one case the signature on the DS record was seen as invalid and in another case there was no signature at all. The errors are reproducable, even after waiting for caches to empty.