announce nat pool to ospf

Hi, I'm setting up a pair off redundant carp/pfsync firewalls/routers to perform as VLAN gateways. The firewalls will announce the VLAN networks to OSPF and also will do NAT on traffic destinating to the internet. I'm using a carp interface to announce the NAT pool to OSPF which works

Re: announce nat pool to ospf

using a carp interface to announce the NAT pool to OSPF which works but I'm not feeling very sure about it. I've also tried setting up a blackhole route but failover didn't work on carpdemote. Would anyone suggest a better way to do this? thanks, Giannis This seems perfectly reasonable