Hello
I think it will fit you better having Vlan pool instead of doing that...
Vlan pooling will let you associalte many vlans to a single SSID.
Try not having more than 10 vlans associated to one SSID.
It is recommended that you have small blocks of 254 host... If not you will have big broadcast domains... which lead to ping drop and retrasnmitions...
you still can do /23 but in this case try if you can drop broadcast and musticast on the SSIDs.
Cheesr
Carlos