"Measure Distance" too cumbersome

The "Measure Distance" tool takes too many clicks to use repetitively. I suggest that once you select "Measure Distance" you stay in that mode and the distance will be updated in a window live, where ever you place your pointer, no second clicking required. To escape from the measuring mode, just right click or press the ESC button on the keyboard.
The other idea is to copy Google Maps and have a tiny measuring tool on the bottom left corner of the screen.

Start by locating the existing “Measure Distance” tool and its interaction entry point in Mission Planner. Clarify whether the persistent live-pointer mode or the alternative corner control is intended; done means repeated measurements work with the chosen workflow and the mode exits via right-click or Esc.

Written by the indexing model from the issue text.