Lynwood,
The daemon doesn't care if it deals with a vlan or not.
But for interfaces which are not point to point, you will need a gateway IP, no matter what.
For point to point links, the interface name could suffice, but this is not supported at the moment. There needs to be an IP address for the -g option.
Regarding the possibility of re-detection, this is not as easy as it seems. Re-detection is easy, but another additional route management is needed to be able to delete/change established routes (a new list, additional checks, periodic re-detection). This is a quite big change to be done for possible 1 system on the whole ampr network.
Can't you just detect the gateway IP change (like in a dynamic dns detection script) and just restart ampr-ripd with a new -g parameter? BTW, your ISP gateway (which you need to use as your gw) probably doesn't change, only your IP.
In most dynamic IP use cases there is a router in front of the gateway. In that case, the -g will have the router's local IP as the gateway and would be permanently correct.
Marius, YO2LOJ