Combination report: ability to hide the values of either chart or line

Aside from the HIDE VALUE button that is accessible when viewing reports (which hides ALL the values of a report), it would be nice to be able to hide a value of one of the shown charts/lines.

Example: A report showing both Chart & Line. I would like the Chart's value to be visible, but I want the Line value as a reference line without showing the value of it.