I was wondering if it's possible to create master/slave modes into the controllers to make it possible to have an controller on every site, managing the components locally while keeping the advantages of connecting all sites on 1 controller. Like the auto IPSEC on site to site VPN, shared Hotspot between all sites, moving devices from one site to another. 

With this feature we can keep all advantages of using 1 controller while creating a fail safe operation if the connection between remote controller and site drops due to a fault or maintenance. For example updating the core switch or router on the main site causing downtime to the portals on external sites.