Multiple Ember application instances in a single page

Hi everybody, we use Ember at work and I wanted to share and get some feedback about our application design.

The application we have built is not a pure single page application, but a mix of ASP.NET WCF and Ember.js. Basically there are widgets written in C# each of which wraps a single Ember application, widgets can be dragged, dropped and configured via an old in-house CMS kind of system. The application is a SAAS offering and needs to be highly customizable, for example, designers know broadly what kind of data is available on a page so designs for each new client involves presenting the same old data in various new ways.

I believe this much background is sufficient for following questions.

  1. What is the precedent on embedding multiple applications on a single page?.
  2. Is this multi-application approach even tolerable? (to me it is not)
  3. Somehow we keep running into the problem that data from one widget is needed by another. How do we avoid that?.
  4. Over the time WCF usage has receded and any UI development now is done only in JS, which brings forth the question of mixing WCF and EmberJS, what are the community thoughts on this?