Hello Jonathan,
maybe the simplest solution would be to use Windows own zoom functionality. Microsoft provides following documentation for this purpose.
Other approach would be to redesign your application to be bigger in size. This means, however, that you have to prepare the assets in 2x, 3x, etc. resolution and also adjust the position/size of all GUI components/views. This approach is thus more labor intensive and more adequate if you really plan to integrate a bigger screen in your final product.
Other option: you can modify the implementation of the ewapp.c module to create a bigger Win32 window and scale the Embedded Wizard generated contents. In such case you also will need to adapt the mouse/touch coordinate conversion. This approach expects some understanding of how the integration between Embedded Wizard and Win32 is working. The implementation of ewapp.c is inline commented and it is explicitly intended to be adapted by the customer to his/her needs. For now we have not had such request so that we could not verify this approach in the practice.
Finally, you can use WebGL as target system instead of Windows. The application is then running within a Web-Browser which is convenient for demonstration purpose. All browser allow you to zoom the displayed contents. Please note: unless your application is small this approach expects that you license the WebGL Platform Package. For more details see Getting started with JavaScript/WebGL.
I hope one of the options helps you to solve the task.
Best regards
Paul Banach