Using a second measure in charts where partitioning for criteria is used

Normally it is possible to add a second measure to a chart, like having a count or a sum on the primary axis and a time on the secondary axis.

When partition for the criteria displayed in the analysis is used, it is not possible to add a second measure. "Add measure" is deactivated.

Why should it be implemented: This will give more context to such charts and save space in dashboards.