In the 11.16.4 beta, Set COLUMNSTOGGLE=columnlist,insert inserts nearest where you right-clicked, instead of always inserting to the left of the column.
Is it possible to add something to do this when we want to insert single column from header menu.
I noticed the same and fixed that earlier. Not sure if it was officially supported or just an internal mechanism for making "columnlist,insert" work, but it's officially supported now and will be documented the next time we re-compile the help file.