> If a Kantian can be put into a situation where their morals would require them to say the word that gives up Anne Frank, we can safely say it's a bad moral system.
Not unless you can present some proof of this. Your implicit assumption that we should care about outcomes over principles has its own set of moral failures, like the repugnant conclusion.
Yes yes I'm sure smarter people than me have done lots of interesting logical things to philosophy over the last thousand years.
And I maintain my simple point: if your ethical system doesn't allow the flexibility to not give up Anne Frank, it's a bad ethical system. Unless you believe giving up Anne Frank isn't wrong? Then you're a bad person and shouldn't be considered in conversations about ethics!
Design it in a way to have good outcomes if you're worried about repugnant conclusions. Personally I believe putting it on paper is a fool's errand - vibes based ethics seems to work as good as one can get from an ethical system.