Would be nice if we could make the legends editable. When you start stacking segments and metrics for a series the legend becomes rather long and cumbersome to have in a chart. I know I could resort to using calculated metrics and/or abbreviating segment names but I want to make sure even then the calculated metric or segment has a meaningful and descriptive name so kind of back to square one
Example I have a work space with 2 series comparing the last 30 days to the previous year same 30 days. And I have the workspace using device and site section segments so the legends become; Unique Visitors[Desktop;Manage Booking Flow;Last 30 Days] and Unique Visitors[Desktop;Manage Booking Flow;Last Year 30 Days] . The legends take up so much real estate in the chart the visualization part is lost. And on the subject of real esate seems like there is a lot of it wasted at the top with the Panel heading and then the segment heading (which I am not using so its totally wasted space.
In report Builder I would simply title the report something like Desktop Manage Booking Flow Visitors and I would label the series as 2017 and 2016