I'm expecting to see talks (and buy books, read blogs...) in 3 years by someone who spent a lot of work adding contracts to a small but significant code base. This is the type of question they will answer.

I think the right answer is in the header, and in turn that means someone needs to answer your objection - how do you avoid long compiler times? I suspect modules is a large part of the answer, which means the guide/talk will also be how to make modules work in the real world. Remember though, that is all guesses I wouldn't be surprised if I'm wrong.