I tried manually accomplish this by editing the scripture item in schedule. It's possible but had a program crash when a specific condition happened. If you use Ctrl-Enter to split only slide the second slide has no label and cutting first slide label to paste on second slide crashes EW during paste operation. If two slides and you perform action on first slide there is no crash. However doing it on second slide does crash program. If last slide doesn't have label you can't paste text into label, unless it was in clipboard prior to starting EW.
So if you want to manually set reference to appear only on last slide do not use paste instead type reference in.
Also noticed widows/orphans in automatic verse split logic, e.g. "4 And God" left on slide #1 when using Genesis 1:1-6. When copying and pasting verse numbers in text view it loses formatting but using slide text box it is retained.