Kibana Metric Visualisation - Controlling Margins / White Space

I have a simple Metric Visualisation in Kibana

MetricVisualisation

It uses the space very inefficiently: here the metric font size is 18pt and this is the minimum panel size to avoid vertical scroll bars. In fact if I shrink the metric font to 14pt I can't shrink the panel without scroll bars being added. What's more, removing the panel title doesn't help either - it seems to still "reserve" space for the hidden panel title when laying out the panel content.

It ought to be possible to control the margins/white space borders to allow the user to make better use of available space on a dashboard and avoid having to use over-sized panels.

Any advice on solving this please? Is there a solution to this.