currently is is required to login to each client separately to do anything, which is just painful and too time consuming.

There needs to be a simple way to view and manage all doamins/reports from the reseller console.
See how EasyDMARC have done it, which is much more intuitive and easy to use.

Most clients do not need their own account and login, as they are never going to use it, thats why they are paying for a managed service.