Objective morality: how would it affect your judgement/actions?

[The Grand Nudger]

Let's say you discovered that you are incorrect about some position you currently hold. You have concluded so far that, "A is a moral/immoral action, under circumstances C". Add whatever other caveats you like. Now imagine that you have access to "moral facts" somehow, and that it shows the opposite to be true.

Which of your positions would you be willing to reverse?

Any of them, and I've changed many.  Even the lowgrade esoterica of production ethics presents opportunity to engage in a moral assessment.

Would you now act differently, and judge others acting that way differently?

Depends.  If I thought that eating spinach flavored icecream was immoral and I learned better..I still wouldn't run out and grab a tub of spinach flavored icecream..and I'd still think that people who ate it were disgusting...but I would realize that they aren't immoral.  

Personally, I don't care about any such "facts", as I feel it would represent nothing more than some specific way of evaluating actions. Without a supporting argument as to why I should change my position by adopting this system, I won't be changing my actions or my judgements. I don't see it as a factual matter.

Moral realism does present a specific way of evaluating actions.  Moral actions..particularly.  If you learned/believed that producing some x or producing it in a specific way was immoral...in the simplest sense, because it caused or could cause immense harm, even if it was productively convenient....then you might be compelled not to produce that x or produce it in that way.

If, later, you learned/believed that it was not in fact immoral to do so because it did not cause immense harm (or the specific harm implicated) then you would have no moral reservations about producing that x.  You may even feel compelled to produce that x, if your area sorely needs more of it.  You may even feel compelled to produce it in a particular way...in order to service that need or because of a range of other benefits to the model.  

These changes in moral assessments have profound effects on people and businesses.  I've described...above, the general moral arc of producers that opt into and out of organics.