Are you still trying to figure out what do with SharePoint Hub Sites and how to control the 100 hub site limit? Flow can be your answer by incorporating an approval flow to the SharePoint administrator. In continuing with the development of Flow integration to SharePoint Online according to the latest October release notes: Site owners will be prompted to create and run an approval process whenever they want to join a hub site in their tenant. Furthermore, for organizations that have turned off self-site creation, users can now request a site to be provisioned, which will initiate a request to SharePoint administrators before being provisioned.
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