I implemented your solution for changing the cursor, but it looks like the icon for the cursor when hovering over the column resize and freeze pane is not consistent.
When resizing columns that do not have the freeze pane, the cursor is a line with two arrows at the ends. However, the resize is a hand cursor for resize when the freeze pane is present.
I would think resize should always be the line with arrows, and the moving of the freeze pane should be either the hand or something different. I don’t think it makes sense for resizing to be the line with arrows sometimes and the hand at other times.