Gumball scale handle problem

The selected line is parallel to the Y axis, hence the gumball does not show the X scale handle. After relocating the gumball and orienting it perpendicular to an other line, I’d like to be able to use the X scale handle to scale with a factor of -1 to mirror the line. Instead of -1, this could be any other factor too. Due to the fact the original line is parallel to the Y axis, the gumball never displays the scale handle. A second object, for example a point somewhere beside the line can be selected to trick the gumball…

Would it be possible to improve the gumball behaviour so it updates the scale handles after rotating the gumball? I think it should automatically snap to the current bounding box of the object.

So instead of this:

the gumball would change to this:

A line which is 0.001° off parallel has a scale handle which disappears when it is dragged away to resize the scale domain.

A line only 0.1° off parallel has a gumball with both X and Y scale handles. They can be dragged no problem.