Can you add an empty column in the row header?

To show an empty column, just omit the display property from the rowHeaderColumns array items.

However, the first column will display the name of the resource even if you don’t specify the display property.

To clear the content, you can use the onBeforeRowHeaderRender event:

onBeforeRowHeaderRender: args => {
  args.row.columns[0].html = "";
  // ...
}