Subdomain Single/Multi Zone

Hello,
I am struggling a bit with the configuration of a zone including subdomains
I delegated a domain abc.de successfully and assigned a single zone to it

Now I can create A records for

  • home.abc.de 1.2.3.4
  • cloud.abc.de 1.2.3.5

The zone itself points to 1.2.3.3

How can I update these assigned ip addresse from each machine separately?

If I use http://ipv4.dynv6.com/api/update?hostname=home.abc.de&ipv4=auto I get a 404 Error
(updating abc.de works)

On the other hand i could delegate the domain as multi zone. Then I can update the subdomains like described but abc.de cannot be configured to resolve to 1.2.3.3

Am I missing something or have an error in my thinking?
(EDIT: Another possiblity would be to add NS records for the subdomains at abc.de and create zones for each subdomain, which could be updated then)

Thanks
Christian