Oh there another event in the white desert that involves the stop light? Unless you mean the girl you use it on, and she grows the extra arms.
No, there aren't any others, my bad! Monoko is the girl with the extra limbs! However, there are still two or three events to find.
I do play this game from time to time. I might binge play the game again someday, I like exploring in the world of Yume Nikki just to escape for a while.
Yume Nikki and its fangames are always a treat to enjoy. Their atmospheres are easy to get lost in. Have you played any fangames?