We are not working on our own extension manager at the moment. From our communications with Adobe their extension manager should still work. It is working on my machines (after several reinstalls). Some people have reported better success with the DWMX extension manager, although I haven't found it necessary.
I wish I knew what Adobe did and why it works for some people easily and others have to jump through hoops like you have experienced. So far I don't know of a reliable order or steps to get it working correctly.