While the feature is in beta, there's also no limit to how much storage space you use up, and there's no auto-delete function after any amount of time, so feel free to upload to your heart's content.
Customers can also preview the app in real-time on their iPad, a time-saving feature to ensurean accurate look and feel, and update their Single Edition apps at no additional cost after they have been submitted to (and approved by) the Apple App store.