Here’s how to do the equivalent of making a circle with a mechanical compass, in MacroGen. My instructions read:

To find the Shoulder Point strike an arc from the Bust Point that is the
Bust to Shoulder length. The Shoulder Point is located where this arc
touches the Shoulder Width line.

Geometrically, that would look like this:

where the radius of the circle is the measure Bust to Shoulder. But you
don’t have to actually create all those arc points to make a circle.
Instead, use the Line Distance point type. It finds a point that’s on a given line, a certain distance from a given point. There’s some trigonometry done for you when this runs. The dialog box goes

where I previously set up points CH and CH2 to define the “Shoulder
Width” line. Note the “C-Clockwise” checkbox. This is for choosing
which of the two possible intersection points (see the red circle above)
is used.