>if the model can recognise incentives to break-in to achieve results, perhaps it can be incentivised to not cheat because it will lead to failure.

This only works if you never give it impossible tasks. A small chance of getting away with cheating beats a 0% chance of solving something impossible. And as models get smarter, they get better at recognizing when something is impossible, while human abilities stay the same.

You can't solve this problem by rewarding refusals to solve impossible tasks, because that only incentivizes false claims of impossibility.