Group Sort Expert (ref prev conv Secondary Sort?)

Hi

Can someone brief me on the limitations of Group Sort Expert (as referenced in previous conversation titled "Secondary Sort?")? I've tried using this before and every time I've noticed no change after attempting, even with explicitly Refreshing and Saving and Reloading.

Current attempt is a report grouped by Product (1), then Width (2), Height(3), and StockID(4). The only filled sections are Detail (suppressed), and Height Footer.

When I pull up Group Sort Expert, the only option listed is Height (because it's the only filled section?). When I select Group Sort - All, the only "based on" selections offered are four Σ sum fields. No option to use any of the formulas used in the Height Footer. Even when I choose one of these, it has no effect on the report display.

Pointing to documentation is fine.

Thanks!

Matthew Tallon