Migrating from pfsense, which is live with voip connections, to opnsense

[normanb]

I am attempting to migrate from pfsense, which is live with voip connection, to opnsense while minimising downtime.
In an attempt to avoid downtime I create Vmware vm with corresponding number of nics, memory and disc space, then used this vm to try and prepare a config.xml file for opnsense.
This went well until I opened the system/gateway page where I found that my PPPOE WAN interfaces were marked as defunct. This prevented me using these gateway to configure the firewall entries (nat and rules).
As a workaround to this I created Virtual IPs for the WAN interfaces which removed the defunct gateway setting and allowed me to create the firewall entries.
Am I taking the right approach or is there a better way of achieving this?