It would be super helpful and add to the aesthetics of the interface if when in measurement mode and placing points if the cursor point turned to a crosshair with an enlarged view off to the side. I have used this type feature in other measuring tools and it greatly helps with accurate placement of points. I will try and find a screen shot to attach to this request. This is one implementation below. See red magnified circle with pointer in upper left. As an added bonus you can also click on and move any dot after placement. How cool would that be:)
This is using the tool on a phone.