What's up with K-AI and Generic e-Charts?

I have the feeling that K-AI and Generic eCharts are not very well alligned. A year ago I could describe roughly what I want to do and today even the most precise description of the task does not lead to a proper plot.
Example:
Input-Data: Table w/ 4 columns: id, Part, Operator, Measurement

What I want to have: A nice box plot with Part on x, Measurement as y and Operator as color.

What I “tell” K-AI: “I need a box plot from the input table. X-Axis is Part, Operator is Color and Measurement is y”

What I get from K-AI:

// No data is available, so we cannot create a box plot.

// Returning an empty option with a message.

option = {

  title: {
    text: 'No data available',
    left: 'center',
    top: 'center'
  }
};