Folks, I needed a switch with 12 VLAN ports and a DHCP server for both the VLAN interfaces. So in my first effort, I deleted the wan6 and wan interfaces. When I tried to save and apply, it lost connectivity to the device (even the device link light went off). This a snapshot and so some bugs were expected. I think if I knew how to use UCI, it may have been more efficient.
I then detached one LAN port (Lan 12) and turned that a bridge device and an DHCP server interface called SOS. From this interface, I configured, touching one or two interfaces at a time and got this working.
I will know more after some usage but I think its configurators (LUCI) have defects.