So, you didn't see our video, because you don't know where to set specifications.
As I wrote, you can create several specifications for each category and several layout tabs. Each layout tab can be assigned to own category of posts.
If you want to save your time - recreate your site using woocommerce instead of posts. This is more easy to use for sites with different categories and more easy to fill all products. See my previous message. Product will have another look, but maybe even better