For POC you can (and should) generate temporary license and use it. It can be installed on a ZD without support, but you will be still unable to upgrade firmware on it. So you probably prefer to have unit with support to make better POC. Of cause, it's easier to make POC with vSZ -- as it can be installed any version needed, and automatically has full demo licenses for a 5 APs per node for 45 days -- very convenient to make POC projects, and if customer accepts, this installation can be converted to production just ading permanent licenses and support.
Speaking about ZD, Permanent licenses are tied to ZD serial-number and can't be moved at all. Support is also tied to ZD serial and can't be moved to different device.
The only exclusion is RMA --when you make RMA for faulty ZD, new support and license are generated for replacement ZD serial, as required.