You do not need a support contract to buy additional AP licenses and install them in the Zone Director. But a support contract is required to upgrade the ZD's firmware and to request assistance from Ruckus Support.
But typically ZD license files are assigned to your Support site account and the file should be available when you sign in to download. The licenses are an encrypted file tied to the Serial Number of the ZD that you upload to the ZD. ZD licenses are not transferable between ZD's except when a ZD is returned for RMA.
I hope this answers your question.
Thanks for choosing Ruckus Networks products, a Commscope company.