My router is connected to a IPv6 overlay network backed by bird/babel with dozens of xfrm interfaces of strongswan/ipsec. These interfaces are created on demand and prone to change.
There are several NAT64 services in the overlay network. I am attempting configuring 464xlat on my router to route IPv4 traffic (except those of strongswan/ipsec) to NAT64 services in the overlay network. But there is no fixed wan device (tunlink) for outbound 464xlat packets as expected by 464xlat.
The tunlink check by 464xlat appears not to be necessary.