Prevent FES from creating post WITHOUT returning an error

Hi,

The error is created during the internal saving process. If you want to handle the saving posts yourself, then you need to break the plugin’s saving process.

I think that can be done with the hook rwmb_frontend_before_process, like this:

add_action( 'rwmb_frontend_before_process', function() {
   // Save your data
   // Redirect users to your confirmation page
} );