Could they get around this by just making a different "app" per customer, with the same code but a different name (or whatever is used as a unique I'd)?
4.3 Spam
Don’t create multiple Bundle IDs of the same app. If your app has different versions for specific locations, sports teams, universities, etc., consider submitting a single app and provide the variations using in-app purchase.
From: https://developer.apple.com/app-store/review/guidelines/#spa...