Enable users to dynamically adjust the number of column controls (e.g., 2, 3, 4, etc.) directly by clicking on the column control itself.
you can already just simply change the source block, going up in number of columns : nothing lost, going down in number of columns, you will orphan the content of the removed column, you still need to move it or delete it afterwards
perfect but what about adding in on control its self not in the properties
Ah oke, now I understand the question.
For me, it is good enough as is.
I still don't know what you mean with adding in on control. Do you mean dynamically adjusting columns with JavaScript or something else?