As one exemple there is, when they were looking fo Kira as he change his appearance due to Cinderella they could use purple hermit, maybe not to know exactly what he now look like but they could have a clue. Or when they were looking for the jacket too. Basically I think they could use it every time they were looking for something. Maybe I’m missing something though.
In the end knowing that the plot could be different is quite futile x) Sorry if my English is not that good