Setup mode is a way for organizations to rapidly modify Roles and Circles, especially when they're getting everything entered into GlassFrog for the first time. It replaces the more involved process of Governance Meetings or Asynchronous Proposals as a way to modify the structure of the organization.
While in setup mode, no notifications will be sent for changes made to circles and roles. However, notifications will still be sent for role assignments.
Governance Meetings and Asynchronous Proposals won't be available while you're in setup mode.
Only Admins are able to make changes while in setup mode, or turn it on or off.