Double-Click Header/Line Numbers to Create a New Column/Line in Cell Selection Mode.
Double-Click Outside to Create a New Cell in Cell Selection Mode.
Suggestion:
Is it possible to make these two options also work for non-Cell-Selection mode?
Issue 1:
Enable these two options.
Double-click to create a new column.
Undo.
** The new column is not erased, unless I refresh the view manually.