I want to notate fingering in which an artificial harmonic at the fourth partial that changes pitches but keeps the same fingering, e.g. 4 over a 1 but I can only get the bottom note. Is this a result of the new harmonic functionality?
You indeed cannot specify a fingering for the harmonic notehead at the present time. I suggest you write the harmonic the old-fashioned way for now, i.e. by writing a dyad with the appropriate pitches, setting the notehead type for the upper note, and then adding the fingerings.
I ended up just using shift + x to type the fingerings in.