There is an upgrade to the BuddyNS service, they are introducing DNSCurve encryption lookups (or something like that - I haven’t looked into it yet) - and two of their servers have been moved to upgraded infrastructure (change of IP addresses).
The External DNS input field of MiaB only accepts IP addresses, but on this delegation config page they suggest setting a hostname.
I have not updated yet, but doing an nslookup on the moved servers (Germany & Canada), I guess if I needed to could just use the IP address in reply.
The upgrade goes live April 20 said an email I received.
Happy to keep discussion and testing.