For what it's worth (not a lot, I guess), as a tireless reader I seldom take any notice of chapter titles. I take so little notice in fact that I had read a lot of Discworld novels before realising there were no chapter titles or numbers at all.
For a novelette, if structural reasons really demand chapters, I would go with simple numbers. Preferably not Roman numbers.
In paper books, chapters, whether numbers or titled, are helpful to many readers who, like me, do not fold corners or place books face down when interrupted, but close them, and then later riffle through to find the place. They act as landmarks in what might otherwise be a featureless forest of text.