I have found a way to implement the 'zoom' function into other templates by going into the CSS option in a template that already has it enabled and copying that. Then in a new template, it's a matter of finding the corresponding images which are located in the 'preview' html files' source code. Once you find the right images and the Page.html name your ready to add it to the CSS in the new template. This is a clunky way of getting this feature to work but there just doesn't seem to be any other way that I'm aware.
Incidentally, after some research I've noticed that this is an extension of the Media Query function which was incorporated into CSS from CSS2. I did learn CSS but Media Queries weren't around back then. I'm also thinking that this function is not a standard feature of Templatetoaster. I do like this program because it saves a lot of time creating themed templates which is why I am a subscribed user and are using the Professional Edition. Perhaps it could be addressed in a later version?