This is a good point. Some of the techniques that I employ today (prototyping at a large scale) are ones that I can employ simply because I have experience and

This is a good point. Some of the techniques that I employ today (prototyping at a large scale) are ones that I can employ simply because I have experience and can see ahead to what potential problems there are in various designs. These things aren't obvious to a junior developer and letting them get too far with a prototype can be dangerous.