Unfortunately, the current design of imfreehand doesn't allow programmatic placement of the tool given a set of vertices as input. This is a known enhancement request from other users.
If you want to query the position of any of the ROI tools in the toolbox, you should use the method getPosition (as you suggested) and avoid digging around in the HG innards of the tool.
h = imfreehand;
pos = h.getPosition();
As a workaround, you could achieve approximately the effect you are looking for by creating an instance of impoly given the position of your freehand tool. If you use the setVerticesDraggable method of impoly, it will visually appear identical to imfreehand.
h_poly = impoly(gca,pos);
Hope this helps.