IME there is substantial variation potential between different caps, regarding time to click, heat level at click point, and exactly how the cap clicks.Hm – I'm always looking for the second click and consider the first one a „pre-click”. The first click is also much quieter than the second one.
Some will double click very close together, i.e. in quick succession, so there is no second clip but more of a double click each time.
Others, a faint half-hearted first ckick is then followed almost immediately by a bigger "pop".
But the strangest thing about this cap variability is how one of my caps, it hits much harder, takes like 60 seconds to cool down ckick often, and always two or three times as long as my other cap.
I can keep drawing for ages, mega long hits I have to stop eventually. And then I still can wait for the cool down click long after I have fully exhaled my hit.
I need to be less aggressive with the torch using this heavier hitting cap where as with the other one I need to be deliberately aggressive with the torch to get sufficient and satisfactory extraction but there is hardly any chance of overheating a load.