DDNS Opnsense vs ddclient

[tracerrx]

Beginning with 23.1 I have started having problems with ddclient not detecting the default gateway in multi wan environments after a failover and failback.  When i change the back end type to "opnsense" it seems to work just fine... What is this magic "opnsense" back end?  Is it the old ddns client that was replaced with ddclient?