I was a bit surprised to see that you can enable mesh on the Zoneflex R320 ap on unleashed firmware version 220.127.116.11.212. It's present during the initial setup wizard and also later on in the GUI. I don't think mesh is supported on the R3x0 AP's so is this a bug in the firmware?
R320 when working as Unleashed Master role can facilitate mesh setup and configuration but it can’t participate in mesh operation or act as mesh node like running as RAP or MAP or eMAP.
For example if you have 1 x R320 and 3 x R550, then you can choose R320 as Unleashed Master and setup mesh network while the actual mesh will only be running on the R550 (ie: first R550 as RAP and the other two R550 as MAP) and the R320 can still provide WLAN service but not involve in mesh operation.