I've tried explaining the implementation word and word and it still prefers to create a whole new implementation reimplementing some parts instead of just doing what I tell it to. The only time it works is if I actually give it the code but at that point there's no reason to use it.
There's nothing wrong with this approach if it actually had guarantees, but current models are an extremely bad fit for it.
For actual work that I bill for, I go in with intructions to do minimal changes, and then I carefully review/edit everything.
That being said, the "toy" fully-AI projects I work with have evolved to the point where I regularly accomplish things I never (never ever) would have without the models.