Indication when selection box is too big

When dragging a selection box there's currently no indication that you're selection is too big. When selecting trees for harvesting it just ignores the box when too big. When creating a mine control area it's even worse as you have to reselect the tower and press the edit button again.
How about turning the box red if it's too big, and a warning message so we know why it's red. And if editing a mining zone it would be nice if it defaults to letting us try selecting again instead of starting over.