Hi Scott,
Thanks for posting.
We investigated loading mechanisms for client-side dependencies with the release of ExtJS 4. In terms of dependency loading, Deft JS seems to be a slightly different take on the Ext.Loader utility currently available.
http://docs.sencha.com/ext-js/4-1/#!/api/Ext.Loader
This works well for us in development environments where we want each of the dependencies to be served individually. I would not recommend using this in a production setting for performance reasons. In production, we tend to use the minified dependency libraries that can be declared in LabKey:
https://www.labkey.org/wiki/home/Documentation/page.view?name=scriptdepend
Note, this is not done at runtime, but does allow for ExtJS-independent script packaging.
As for the MVC portion of Deft JS, we don't use ExtJS MVC extensively. It is interesting to see what people consider areas for improvement in Ext's take on MVC.
Thanks,
Nick