Allow better editing of tab-stops in text so that the dialog does not have to be closed for each and every tab that is entered into a text object in layout mode. Without a visible ruler in the dialog box, you have to enter tab stops by knowing their exact numeric position which is almost never the case. Tabs are more often set by dragging one of the arrows left or right in the ruler bar.
Make it more like a word processor, you can drag and set and apply without having to know the decimal numbers for the tab positions.
And for goodness, sake, give it its own menu item, especially in Browse mode where it is too deeply buried in Format -Line Spacing - Other ... and then a TABS button has to be pressed. Way too obscure. Most of my colleagues say they never knew it even exists there.
(just noticed, by the way, that there is no category in this Create Idea thing for Layout. Seems to me a big omission.