Guinness ice cream -- what the...?

The Boston Globe today offers a recipe for Guinness ice cream -- though it's really a frozen custard.  Boston may have great ice cream shops (or "shoppes"), but custard is more of a midwestern experience (and even a religion in Milwaukee).

I believe in cooking with beer (and routinely throw a bottle of whatever dark beer I've got on hand into my vegetarian chili) but this recipe seems a little extreme.  More precisely, I don't see it working right.  I'm afraid you won't be able to taste the Guinness due to the molasses, and someone who cheats by using vanilla extract (instead of real pods and seeds as called for in the recipe) will run the risk of screwing up the custard from all the alcohol (there's not a long-enough boil to burn it off). Plus, the recipe merely points to the last, most critical step -- "process the custard in an ice cream maker according to the manufacturer's instructions."  Until I see Irish Cream Stout as "flavor of the day" at Kopp's Custard, I'll pass.