Visibility settings issues in Power BI

[ruthpozuelo]

Is your feature request related to a problem? Please describe.
I am playing with the visibility settings in Charticulator and having the following issues:
When defining the visibility settings (in the case below, the text on the secondary x-axis), you have to pick a hard coded value:

and that brings a few issues in Power BI:

1. If the category or field does not have a value for the picked category, the text doesnt show:
   

and if a user filters the chart by another field that does not include that category, nothing will show:

Describe the solution you'd like
Ideally, the values would show independently of it that category has a value or not and instead of picking a hard coded value, maybe we could pick "firstnonblank" or "first" or "last" or a measure to define the visibility, like " first selected nonblank value"??

Hopefully I managed to explain myself!