Agreed, its the only way to seamlessly use the Site Context if we have full control over the CAD data. However if this is not possible, I believe my suggestion would help a a lot in terms of integrating the native site model with the Site Context.
I am loving the new update, especially the Site Context feature.
I have a suggestion for an update to improve the Site Context feature. I think a reverse of the 'native site' feature would be a good idea. Essentially a feature that lets you carve out the part of your site which is modelled so it can sit within the surround context better, for things like cutting further down into the site etc is currently problematic as you cant adjust the topography. So a simple way to cut out the Site Context using the extents of the native site would be a good idea.
Also in terms of the context it self, I have noticed some of the more rural areas which I tend to work on is not yet modelled in the Site Context, is this something that will always update or is the data just based upon a external source?