legend layout improvements

From a user voice request

legend layout improvements

it would be nice having

  • line-break / feed in legend headers, e.g. for displaying the unit in a second line
  • ability to remove the display of the highest and lowest values (which are always there and they are not aligned with the other values)
  • Ability to choose the labels, much like the “new value” / “new range” buttons of the slice filter

instead having an option

Dev note: some of this may already be available