We just launched a sample template gallery as part of the ReportingCloud portal. This gallery should help you to understand the supported reporting features in templates.
The uploaded templates are tagged and can be filtered by these tags. When opening details of the template, a description and an animated preview of the merge process is shown.
Using the button Add to My Templates, you can add this sample template directly to your template storage. The sample data source will be copied and linked to this sample template automatically.
Test this on your own and register for a ReportingCloud trial account today.