A month ago I wrote: "TechSmith is very smart when it comes to understanding their audience and software features. They're not going to build it because then you will have zero reason to buy Camtasia."
Allowing a fullscreen Web cam video into the recording fits within the existing SnagIt feature set. Allowing you to resize that Web cam video means they have to take existing features in Camtasia and put them into SnagIt. And introduce multiple layers in the editing timeline.
Snagit is excellent. It is great that you have included webcam, which I requested many years ago. However, the webcam is almost useless unless you can downsize it to fit into a corner of the full screen, showing it and the presentation simultaneously. Hope this will be a feature in the first upgrade?