I'm guessing your client is using the Ruckus 7372 as standalone correct? If so what router are they using? Take for example one of my own clients has a Edgerouter Lite setup with POE switch (that supports VLANs) and a Ruckus 7372, Basically I setup, two VLANs for them, One for their internal use network and security cameras and one for their guests. For example, for one network I setup VLAN 2 and the other network as VLAN 4. So on the Edgerouter Lite I setup VLAN 2 with one DHCP server for say 10.1.100.x and on VLAN 4 I setup another DHCP server say 10.1.200.x. Make sure you trunked VLAN 2 and 4 to the POE switch which then get VLAN 2 and 4 trunked to the Ruckus 7372. Which then you setup one SSID for VLAN 2 and another SSID for VLAN 4.
Note: if you got something like the Edgerouter Lite or X, I know for the EdgeOS you have to define firewall rules to block of the different subnets of VLANs from contacting each other.
Or you can also setup a PFsense Router, but would cost more. Right now I say a cheap reliable router would be either Edgerouter Lite or X. However Edgerouter is not easy to setup like a consumer wifi router. It does take some know how especially for more advanced functions.
So what is your clients network structure?