[armsaw]

Often the issue is with mDNS device discovery across vlans or subnets, especially with IoT / home automation type devices.

What you are doing with SSIDs will not create any segmentation on your network, unless you have implemented either vlans or subnets, and corresponding firewall rules to gate traffic.

[stavros]

Sure, but routers that offer that feature generally tend to segregate the VLANs for you. And you're right, multicast won't work.