But the thing is, there's no way to get feedback on what they're doing wrong. If you make bad crypto in your prototype, then to you and most everyone else it w

But the thing is, there's no way to get feedback on what they're doing wrong. If you make bad crypto in your prototype, then to you and most everyone else it will look just fine, so you'll get no feedback on misleading feedback. You won't get the chance to learn from your mistakes because you won't know what was a mistake. You'll get realistic feedback only if someone skilled spends nontrivial time to analyze your solution (likely more time than it would take them to just implement a known good solution) - which will happen only if you hire them for an in-depth audit, or if you launch a production system where breaking your crypto will have a big enough impact to motivate someone to break it.