@mzator
if you would like to replace the global admin account with reduced permission
then each O365 app has its own requirement
- Sharepoint online app minimum required would be sharepoint administrator
- Teams app requires teams administrator
- Exchange app requires exchange amdministrator
- Onedrive for business app requires onedrive administrator
Global admin account is mainly leverage for creation of appid and verfication of same inital configuraiton
few of the O365 apps uses azure appid only for discovery and backup purpose too
some reference in documentation (sharing for one app)
https://documentation.commvault.com/v11/essential/134726_give_azure_service_account_access_to_sharepoint_online_sites_in_basic_authentication_environment.html
The Office 365 with SharePoint (SharePoint Online) administrator account must have the following service accounts configured:
A SharePoint Online service account, which must meet the following requirements:
Must have either the SharePoint administrator role or the global administrator role assigned so that the SharePoint administrator or the global administrator can discover and back up the sites. For more information, see Assign admin roles in Office 365 in the Microsoft documentation.