How does the 3/2x drop work with other stuff?

Is there an actual max amount of drop? Say there's 3x drop, i buy a 4 hour drop in cs then the Easter egg drop. Would it be 8x drop or what? ( For example if your fighting mini-bosses to increase scroll/recipe drops )

x3 drop event + x2 card + x2 easter buff = x12 drop.

It's definitely noticeable. PB drops reach both ends if I have x8 or higher drop. Same with horntail and zak.