Query?
You currently use custom attributes and wish to switch and use the Additional Azure AD Attributes feature. Is this possible?
Answer
If you’re currently using the custom attributes feature, you can switch to make use of the Additional Azure AD Attributes feature - providing you synchronize a local Active Directory to Microsoft 365, using the Azure AD Connect tool.
If the extension attributes have been selected for synchronization using the Directory Extensions feature within Azure AD Connect, then the existing custom attribute fields added to signatures will continue to work once the switch has been made and a data synchronization has been run in Exclaimer.