In the measuring tool, the only option is the 1 Form. I suggest there be a second one which lets players select the "Type" of measuring tool for the game they are using. So instead of ".ft" it can use other measurements, Number of squares it would take to get to the square you measure to (like 1 diagonal would be 2 squares), and so on. This will add more versatility.
Another thought would be you click and hold left mouse button to measure, then click the right to keep that measurement while you measure towards a new direction. Say for running around a corner.