Install App as "Default" but allow user modification?

Is it possible to hack to allow the site administrator to install an app as "default", i.e. Blog, but allow the end-user to configure the application in the application area? There is a rich capability to extend and customize ES with apps, which I get, but that brings complexity for users. I would like to make it so the users get the core features of our member site (i.e. Blog, Discuss, Calendar) but also specify if I will allow them to customize the app in the app area.

I thought I saw this might be supported in the future, is that right?

Meanwhile, is there an easy hack I could apply to achieve this now?