Allow Deeplinks for chat to refer to external, federated user IDs
There appears to be no way to add an External/Federated Teams/SfB Contact so that it becomes searchable by display name in the Teams client.
One had hoped that providing a App/Static Tab with a deeplink, such as https://email@example.com , to an externally federated IDs could be used to open a Teams 1:1 chat session with the linked external ID, but this too fails to launch a chat window (since apparently this functionality is limited only to tenant users who can somehow be found in Azure AD)
A debug session shows that the Teams client is looking for a user profile for the linked ID, which of course does not exist in the tenant.
The request is to to allow deeplinking to accommodate external IDs and not just tenant users.