IT can actually give your user necessary rights to do this, but it requires a bit more know how. People usually use the sa, because it's the safe bet, though, as best practice, it's probably not the best way to go.
Can you at least temporarily give the MAS_USER account the ""sysadmin"" role on the server? . then do your migration, then remove the sysadmin role...(assuming all other necessary permissions are there for Sage to operate).