How should I properly cite an author with a variously credited name?
I think the appropriate thing to do is to cite each paper with the spelling that the author chose for that paper. In some way, this is no different than when someone publishes first under their maiden name and then under their married name. Or the other way around. Or when they legally change their name for whatever good or poor reason. Let the author of the paper choose what name they want to use, and use that in the reference.

The reasoning for this is that ultimately, a reference is not meant to educate a reader about the subtler points of identifying the author and their history with family names. The point of a reference is to identify a paper, and the paper has after all been published by the author using one and only one spelling of their name, whatever it may have been the day the paper was written/accepted/published.