I just found out, by accident, that Duncan Butterflies have thick caps that can come out and are the same size as other Duncan caps. So, I put them in my Raptor, out of curiosity.
The thick caps jut out, making them liable to catching on the string. Also, the yoyo was much heavier and had a rhythmic vibe (vibe–vibe–vibe–vibe). And, sleep time was reduced.
What was unexpected is that the heavy yoyo was very fast playing and very steady. With the Butterfly caps, it much faster than it is with the thin caps.
I’d just thought I’d point this out to anyone who was curious, or maybe to someone who could improve on the idea.