In their defence, nobody can implement auto-detecting domains well, because there's no way to efficiently enumerate DNS records.
reply(Excluding NSEC-style enumeration, which is not always available.)
I feel like I'm missing something, AXFR?
replyAlmost no mainstream existing provider you’re migrating from would support AXFR from Bunny’s servers. But yes, AXFR would be the ideal solution in a perfect world.
replyThat's not their fault, though. There's no perfectly reliable way to enumerate the DNS records for a particular domain.
replyI'm a BunnyDNS user and wanted to share a warning - the import from a zone file can drop records silently, and the export will fail to export some of your records. I reported bugs some months ago, they replied they've fixed some but it's still a problem.
replySpirit: ensure you keep a good copy of your zone files (bind format), their import / export has issues (it also doesn't include SOA or NS records). I spent time (before the recent fixes) manually validating records.