Yes, your scenario is supported. Let's assume RV042-A has static IP and RV042-B has dynamic IP. On RV042-A, you can configure Remote Security Gateway Type as "Dynamic IP + FQDN", where the FQDN string, a shared secret between two routers, does not have to be a valid domain name. On RV042-B, you need to configure Local Security Gateway Type as "Dynamic IP + FQDN" with the same FQDN string.