So here is my work-around. Before I download to a csv file, I add a column, and following the save, I make the column invisible. If I save again the same data it does not add another column, probably because the column is the same name.

Solution is not ideal but unless someone can come up with something cleaner, it works! Code for download change is below;

document.getElementById("download-csv").addEventListener("click", function(){
    tableCues.addColumn({title:"id", field:"id"},true);
    tableCues.download("csv", "data.csv");
    tableCues.hideColumn("id");
    });