Summary columns in spreadsheet

I was playing with the summary columns today and I have a couple of questions related to that. In summary:

  • how can I specify which columns are taken into account for individual summary columns? Currently it seems to render all of those but that is mostly not helpful
  • is there a way to show/hide axes for the summary columns (like the bar chart where I would like to see y-axis for the value and x-axis for the column names)?
  • how to handle those columns in the table? It seems as if they cannot be removed or dragged around like other columns.