OneDrive
Professional and single-seat workflows can use OneDrive as the primary source.
SignumEra Start Onboarding Microsoft-native
SignumEra is not another document warehouse. It works with documents from OneDrive and SharePoint, uses Teams as a coordination surface, and writes final outputs back to Microsoft storage.

Microsoft workflow
The Microsoft-native model is a distribution advantage and a user-experience advantage.
Professional and single-seat workflows can use OneDrive as the primary source.
Firm and organization workflows can use SharePoint as the primary source.
Teams can help coordinate signing rooms while SignumEra remains the execution authority.