Sorry for this delayed response, but one of my wifi dongle not work....
I think at this time the only usable application for AVB is the connection between RM Mixer and CS18 to use the Audio in- and outputs on the CS18. This can you do with a direct connection or with an AVB Switch.
The Idea behind this question was, to use the direct connection between RM Mixer and CS18 and additionally a Wifi Network to Control mixes from the iPad, or control Studio One from the CS18 without an AVB Switch.
I have configure out .... this works if you make a self assigned IP Adresse connection with direct connection from CS18 to the RM Mixer and additional a Dynamic Adress Network with the Wifi Dongles to a Wifi-Network Router. Now you have two different Networks with different IP Adresses (One AVB Direct Connection and one Wifi Control Network). Connect all Devices (iPads, iPhones, MacBook can you connect with Ethernetcable) to the Wifi-Router. If the MacBook have a Firewire connection to the RM Mixer you can record the Audiosignals and control StudioOne or Capture via Wifi.
The result.... all features without an AVB Switch
This example is not not verifyed by Presonus, but it works.