Auto growing Matrix

I have a stacked chart using a matrix but we are making regular changes that affect the matrix selection. I have to constantly redo the chart to include the new additions. I also have to select the longest date range possible to ensure I’ve got all options selected. This also makes the graph look messy as all options are on the legend even if they are not within the data.

It would be useful to be able to select matrix by a pillar with an option for it to auto-include all options rather than manually selecting.

The chart below shows that I’ve had to select all 63 options even though only 20 are active but the legend still shows all options.