Is it possible to mark my preview code that generates previews, the JSON files that hold that preview data so as not to be compiled and included in the final application I submit to the app store?

If you look in the project navigator, there is a folder called Preview Content. My understanding of this is that nothing from this folder will be included in a release build. So put your preview related generators/resources in this folder.

To prevent preview data and methods from shipping with the final product to the App Store, follow these steps:

Use Conditional Compilation:

In your code, wrap preview data and methods with preprocessor directives (e.g., #if DEBUG in Swift/Objective-C). This ensures they are only included in debug builds and excluded from release builds. Separate Configurations:

Maintain separate project configurations for development and release. Ensure preview assets and data are only included in the development configuration. Thorough Review:

Before release, perform a thorough code review or automated checks to confirm no debug or preview elements remain. Environment Variables:

Use environment variables to control the inclusion of debug features. Exclude these features in the production environment. App Testing:

Use tools like Xcode’s Scheme Editor to ensure the app runs without preview data in the release configuration. Test the release build to confirm the absence of development assets. Following these practices ensures your app is clean and free of unnecessary development elements before shipping.