I know that, in a bar chart for example, I can display the value of any expression as a pop-up on hover/mouseover by unchecking the visual options (bar/line/etc) and checking 'Text as pop-up'. I can't figure out how to do this in a Mekko, where the bar/line options are checked and grayed out by default on all expressions, meaning that I can't uncheck them. Therefore all expressions are represented graphically, which is not what I would like.
