There should be a possibility to configure vlan id and gateway in subnets. Vlan id should be optional and multiple subnets may have the same id (As a VLAN may contain multiple subnets). That would allow using Foreman as the master for vlan configurations. (name isn't the same thing as vlan id. considered more as a descriptive field)

We, for example, have a installation VLAN where there is a DHCP server that is used for provisioning. At the end of kickstart we'd like to configure the real address for the server (i.e the one the server uses in production VLAN). In production VLANs the servers should be configured to use static IP addresses. If there was a possibility to pre-define all the required information, including the gateway, we could configure our servers ready in installation VLAN and then just change the port configuration from the switch. Gateway isn't always the first address of the subnet so a snippet won't do the job