Is your feature request related to a problem? Please describe.
My problem is that the external ip address of my ingress controller, is not one that is accessible via the internet. It is a local ip address, which is then exposed to the internet via DMZ.

NIC chooses its external IP address (or addresses) when setting the DNSEndpoint entries, however I would like to overwite the target attribute. You can choose other aspects of a DNSEndpoint in the virtualserver so it would be ideal to be able to choose the target or targets here also

Describe the solution you'd like
In the externalDNS struct in the virtualservers

externalDNS:
    enable: true
    target: 1.2.3.4 # Set public ip

Alternatively this

externalDNS:
    enable: true
    targets:
      - 1.2.3.4 # setting multiple targets
      - 5.6.7.8

I do not myself have a usecase for setting multiple targets so would be happy with one.

Describe alternatives you've considered
Using an ingress instead with an externaldns annotation which allows setting the target. This does work for me but I would much prefer to use VirtualServers

annotations: # on the ingress resource
    external-dns.alpha.kubernetes.io/target: "1.2.3.4"

Additional context
external-dns.alpha.kubernetes.io/target takes a comma separated list of targets so maybe this is sensible to follow, and have a list rather than a single target.