But it looks like the files are the same for each package... if someone owns the license for all 3 sites, why it isn't possible to upgrade from a unique package?
I'm asking this because some people have modified files in the XenForo core software... downloading each package and applying the changes manually to the files and then repacking the files to upload to the server and upgrade is a time loss operation.
I know there is obviously some code in XF to check whether if the package being installed is associated with the license/domain. And probably the installer notifies the XF team if it detects that it has been used on a domain not associated with the license of that package... but then when you investigate you'll determine that the other domain has a license associated, but was upgraded using the package of the other license which also belongs to the same customer. So no piracy at all.
Is there going to be troubles for that customer even when he owns the license for both domains?