On a virtual address you can use the dev statement to make sure an ip address ends up on a sepecific interface.
It would be nice to also be able to do this with the excluded-address statement. For instance:
set high-availability vrrp group v12 address 1.1.1.1/24 interface eth0 set high-availability vrrp group v12 excluded-address 1.1.2.1/32 interface dum0