Decision for Disconnect dialup interfaces

[MW]

Hi,
i am trying to set up a OPNSense Cluster with PPPoE dialup WAN.
I Tried the solution provided her https://www.mayrhofer.eu.org/post/opnsense-pppoe-ha/ but i cant setup a gateway after configuration of the pppoe interface.

How does the option "Disconnect dialup interfaces" work? I don't see any options to define how this is triggered.
Is it enough when most of the interfaces are in CARP Backup state?

Thanks for any help!