There are a lot of sketching functions that aren't there yet. We've been using other cad programs and importing the dxf files into HeeksCAD for the CAM operations. One program that works well for that is 'libreCAD' LibreCAD - Blog about LibreCAD, a Open Source 2D CAD program
Draftsight for Windows or Mac and Bricscad for Windows or Linux also work pretty well for this.
While you can do a lot of cool 3d CAD operations in HeeksCAD, the emphasis is really on CAM since there are a lot of really good CAD programs that do trimming, filleting etc.