I think in asking "would I self modify to avoid/encourage x", you're really just asking "Do I want good things to remain being good?" Of course you do, they're good things.

This doesn't at all determine what it is about things that may qualify them as good, just that you desire for things you ascribe with the property of "goodness" to keep that property. But I don't think you're trying to do this--correct me if I'm wrong though.

So, if you never intended to identify moral facts in the first place, and you just wanted some heuristic for determining if something is "morally significant to some individual", you're fine as far as I can tell. Tautologically even.