Currently in order to ensure I extract all material from a corner, I have to draw two lines from the corner with equal to each other and parallel constraints to the existing corner lines that are sqrt(bit_diameter^2/2) then create an arc 180 degrees between the ends of both those lines. It would be great to be able to mark the corner (a fixed point on the arc), radius, arc length in degrees, and then select the start point on the curve which would snap to an existing line intersection like other tools.
Since these have to be cut out of every corner where you need to have a square mate with it you need to do this a lot in some models.