You keep holding on to this as if wishing would make it true:

    It doesn’t matter how you cool it, the answer is always the same.

It does. It really does. All the stuff you're discounting is the difference between "real world performance" and "ideal performance" and even "ideal performance" doesn't get anywhere without conduction and convection at a bare minimum.

Right there. You said it really does matter how you cool it. "The answer" being Q in the equation right before the quote of mine you used. "Q" stands for heat energy removed, which you said can be different depending on how you cool the 100g of whiskey from 21C to 15C.

It would do no such thing.

That's exactly what I said.

You're presuming the glass and atmosphere are perfect insulators

No, I simply know that heat flux doesn't go from cool bodies to warmer ones. Heat goes from warm to cool (glass to liquid.) That's one of the laws (2nd, I believe.)

So, knowing that all of that heat energy went into the ice,

You know no such thing.

Yes, I do. If the ice didn't make the whiskey colder, what did? The warm glass, the warm air, or the warm hand holding the glass? 2nd law, bro.

It's clear to me that you're not going to wrap your head around this problem or how it's solved. I was hoping to get the light bulb to come on for you. You still want to calculate how long the cooling will take. (You and I seem to be in agreement that the spherical ice will cool the whiskey more slowly, so I'm confounded that you think you need to calculate exactly how much slower it is. For me, "well, it's ain't gonna cool faster, that's for damn sure!" is good enough.) I'm calculating how much ice will melt once the whiskey has reached the desired temperature. And as I've said before, the longer it takes, the more energy will have to be removed from the whiskey by the ice due to the heat transfer from the surrounding environment. Again, I don't even care for the precise answer, only "it sure as hell ain't gonna melt less" will do.