The /PART refinement has just been implemented for UTF-8
Enough people have been confused about the purpose of /PART that I wonder if /LIMIT makes more sense. It seems /PART usually has more possibilities than just an INTEGER! of how many series units to add to the destination...where negative numbers can mean something other than "nothing" and series positions can be used.
Philosophically I kind of agree that if /PART makes its way into too many functions where COPY/PART would suffice, it may have a viral nature like the /INTO virus. Finding a more general mechanic--such as being able to make "series slices" without copying them--could keep every routine from thinking it needs it.