Programmatically retrieve Microsoft Office 365 account

I'm trying to programmatically retrieve the Office 365 account in use by users on a Mac fleet. I discovered this is apparently stored in the keychain, either in the msoCredentialSchemeADAL internet password or in the OneAuthAccount generic password (both in *Where* field). The first is sometimes missing, but the latter seems always to be present. Now I found some computers where the msoCredentialSchemeADAL ID is not matching the Office logged in user. And I have two OneAuthAccount entries, one with the same ID, and the other one with the ID matching the user showing up in (e.g.) Word. What's the correct way to obtain the Office365 User UUID? I was unable to sort it out, so far my searches were unsuccessful.