Sorry for the late reply.
If you want to have it over there in the left corner but don’t want the background to block your screen, you can use what you have and simply set the relief of the self.mainBox and the DirectAutoSizer to None by passing relief=None to both of them. That will make the background disappear.
I’m also working on an integration of those widgets into my DirectGuiDesigner which should make it simpler to use and create UIs with them. But that’ll take some more time until it’s ready and fully functional.