First of all, let me thank you for the great extension. It indeed is easy and powerful.
The only thing it lacks (or not obvious) is configuration for file updates. For example, if somebody buys an extension and want to get an update of it. Especially, when updates are free for all, who bought extension before.
My guess, for now I can set link expiration to 100 years and Require Registration to ON and then just update my files via FTP. Am I right?
What about link then? If registration is required and customer clicks on it in email, will Joomla ask him to login before download?