I'm going to make the point I always do in this discussion: I think "dust specks" is a very badly chosen example. Do we really have to make this about literally the least possible discomfort someone can suffer? I think the "least possible" aspect is preventing people from actually multiplying; we are notoriously bad with small numbers, and I think most people are rounding off "dust speck" to "exactly zero".

I propose that the experiment should instead be named "broken fingers versus torture". Would you prefer 3^^^^3 broken thumbs - someone takes a hammer, forcibly puts the thumb on a hard surface, and whacks it quite hard - over fifty years of torture? This, to my mind, at least makes it a question that humans are capable of grasping; a broken thumb does not round off to zero. Or if you feel the thumbs are too much, then at least make it something that's not literally the least possible increment of discomfort; something that doesn't get rounded to nothing. The "least possible" is the least important part of the thought experiment, yet it's the one that causes all the discomfort and angst, through a bog-standard rounding error in human brains. This really ought to be avoidable.