Well, you could just create a new Tour but only using your flat images.. Add a Thumb navigation bar too and the menu with Zoom.. Then add that Tour to a Website Box within your main Tour.
Create a folder named Gallery1 etc, and then name the Gallery build gallery.html.. Then in the Tour add a url something like this. Make sure you add the Gallery1 folder inside your main Tour folder..
../Gallery1/gallery.html
Test this when you build your Tour by pressing the Green button..
Why don't they just make it so all images are by default able to be zoomed into? This seems so obvious to me. When the visitor is in a pano and clicks on a image and the image pops up there is no reason to zoom into the background behind the image. All zooming should now be on the image in the foreground! I explain this issue in this video here: https://youtu.be/vrrr5xUJjP0