Question on Drop Rate

Before my first run I was doing the Kritias daily quests, so indeed I had my wolf out.
But upon entering the Dimensional PQ map, familiars automatically 'go away' since you change channels. So I'm not sure what happened here .. o-o

I know they disappear. But I observed, upthread, that even after the familiar goes away, it still has some effect that slowly fades.
Might last as long as it has less than full vitality, or something along those lines. It bears investigating, but I think that can wait until the more common situations are cleared up.

I've always thought that drop rate potential were additive since it says + and the drop rate events/card/wolf/easter is multiplicative since it says x.
The only drop rate factors that raises questions for me are Holy Symbol, Wealth Acquisition (I assume additive), Showdown, Monkey spirit Kanna and Inner Ability.

I'm not sure about those x's being multiplicative. I know that when exp bonus lines got split up, multiplicative stacking of some buffs broke. So I'd rather check, if possible.
I can't ask anyone to waste events/cards/coupons/potions on these tests, but the familiars and skills just require time and the right class, so hopefully we can get to them.