Using CNC CAM Blender extention from github is a great way to try out the newest features and fixes. The latest build (dailybuild) of Blender can be used with the latest Master branch of CNC CAM extension and then you can live on the bleeding edge.
*don't* extract it. In blender, go to preferences, Get Extension, and select 'Install from Disk' and select the blendercam.zip file you downloaded. After Blender must be restarted to ensure the wheels are correctly installed.