When installing a new version, that would be extremely useful if we could transfer all third-party scripts, plugins, and modifiers to a new version of 3DS Max, without having to manually install them.
Some users, like me, use lots of third-party scripts and plugins, which can take up to one day of work to be re-installed and all set. Saving the UI and the hotkeys do help, but it doesn't prevent the users from having to re-install everything in the new version.