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

Yeah, that's correct. Most of the drop buffs in the use inventory override each other out. Since familiar cards are in the use inventory before used, they act the same way.

I think it goes more on the lines of the buff being stored as a use item in the data, but yeah.

Well, there goes my stupid x12 drop attempt. No NX to get a card, so x6 should do.