I'll copy more of my comment here then, with added links that explain some terms. (No credit to me for the post, I'm just interpreting the result.)

Basically, you've combined two previously existing ideas into an algorithm that's better than either of them alone. The first idea is that moral arguments with shorter proofs seem to capture some of what it means for a moral argument to be "natural", but it's flawed in that it's not clear how similar in complexity are the other moral arguments, and if it's a close call, then the distinction is not particularly natural. The second idea is to use the diagonal method to banish the spurious moral arguments beyond an arbitrary proof length, but its flaw is that we have to know the guarded proof length in advance.

With this algorithm, you're not just passively gauging the proof length, instead you take the first moral argument you come across, and then actively defend it against any close competition using the diagonal method.