Feature Request: Specify Legend height at the top and bottom of visualisations

Hi,

It is possible to specify the width of the legend in Explore when it's right or left, but not the height when it's placed top or bottom.  Being able to specify the height would allow the full legend to be viewed instead of only a single row,  depending on how many metrics/attributes are in the legend this would allow the full legend to be displayed or at least more than one row which is not at all user friendly and not exportable.  In some visualisations it is much more visually appealing and consumable to have the legend at the bottom e.g. Pie charts.

Thanks

Melanie