The CG is currently processing both backups and replicas from other tenants so that should all be functional. The 0365 service is installed on the SP VBR server.
The tenant created on the SP VBR server is added as a service provider
Launch the Veeam Explorer for Exchange and Add Store dropdown and select from service provider
Specify the cloud gateway in the dropdown
Credentials for the Microsoft O365 user are then entered (the ones used on the SP side to connect to the O365 tenant and perform the backup)
Error then is the open operation did not complete within the allotted timeout of 00:00:00 . ... Open timed out after 00:00:00 while establishing a transport session to net.tcp://127.0.0.1:62673/ArchiverExchangeServiceOrg/..
. Those are the relevant bits anyway Logs show an error connecting to the cloud gateway which again seems odd as psping to port 6180 works
One thing I'll mention is we use a wildcard SSL cert.