Thanks for a very interesting essay. Your precautionary warning of moral steering is fascinating. If I am understanding you correctly, you are saying that a moral project leading to some social outcome, which you differeniate from unplanned moral change, can have potentially unforseen effects including outcomes that alter or destroy that morality? This is a fascinating argument and I can see the wisdom in being wary as to the complex and self-referential nature of moral and social change.
If I could ask, wouldn't this also apply to non moral-projects such as technological, business, military, administrative, cultural, economic or any large human project? Moral visions (for example this essay competition?) seem to have been singled out, but isn't morality the product of many many things that are not deliberate moral actions, and wouldn't changes to any of these risk destroying a hidden moral steering process in the same way? In a way, perhaps your warning could apply as a lesson for large human projects in general? Would it also apply to slower, unplanned change, but on a larger time-scale?
If evidence pointed to a moral failure of some kind, such as an impending threat to humanity, do you have any thoughts on the point where a more 'engineered' moral vision might become worth the risk?
Your idea of risk mitigation is quite brilliant, though I am a little confused by your proposed method. My experience with social science has often suggested that isolating factors for mathematical analysis (factorisation) is extremely difficult in the realm of human decision-making such as morality. In the more productive areas of social science that have moral implications, such as experimental psychology (take the Milgram Experiment or the Prisoner Experiment), there has usually been great difficulty in objectively defining factors that can be both quantitatively analysed and also provide accurate predictions in other 'real-life' situations. So perhaps I have not correctly understood your approach (economics appears to be partial exception to this in that there is the discrete objective quantity of price already in place as a starting point).
In any case I think your message of caution in regards to moral visions and understanding their complex social outcomes is extremely thought-provoking. Thanks for your essay. I hope you have a chance to read and rate my own entry!