I understand your issue. I too had this concern.
I am not using Fordson, so I am not sure if my solution will work for you.
I am using the normal Boost theme, and have added Collapsed Topics plug in. What this does for me, once set up, is that the topics navigation in the Nav Drawer are gone, just as you wish. In its place, students can click on a little "target" icon in the topics title bar, and switch to single topic mode. In this mode, students do see all the topics in the Nav Drawer. When they switch back to "all topics" mode, where they can navigate topics in the main center, the topics are gone in the Nav Drawer.
I am one who believes that this is a great solution, and how Moodle should work. Gareth has done a great job with his "Collapsed Topics" plugin to make this possible.
Here is a video that I made a while ago that illustrates what I am doing.