SSIS Package Configuration

Hello,

As per following article, "You cannot use the /Set or the/Connection option to override single values that are also set by a configuration". Can you elaborate on this with example?

msdn.microsoft.com/en-us/library/ms141682.aspx

My other question is if we want to schedule an SSIS package, can I schedule the package without running the BUILD command and preparing a DeploymentManifest. If not why?

Thanks