You can check if this is possible by going to 'Hardware asset workspace' from the 'UI builder'. This is where you will find options to customize workspaces. But I would recommend not to modify this unless there is a strong business reason to add widgets on the success portal itself. The purpose of success portal is to provide an overview of your success goals and projected cost savings from those goals. It gives the option to create success goals and success activities as per your requirements which can be tracked here. For your custom reporting requirements, it is better to add widgets on the appropriate tabs of the 'hardware asset dashboard' instead.
