Hardly any projects really need to implement models in modules. I've been on the board for 1.5 years and don't recall anyone running into actual scale problems. Scale problems are almost always theoretical and rarely actual.
The way it's currently set up makes it really easy and painless to rapidly develop an app. And it's rapid development that you can keep instead of throwing out. I don't know Python all that well but I suspect the better approach would be putting models in classes and then importing them in controllers as needed. The conditional models, models in modules and model map seem like hacky workarounds to me.
