I don't think that the fact that everyone having a different checklist is the point. In this perfect, hypothetical world, everyone has the same checklist.

I think that the point is that the checklist is meaningless, like having a literary genre called y-ism and having "The letter 'y' constitutes 1/26th of the text" on the checklist.

Even if we can identify y-ism with our senses, the distinction is doesn't "mean" anything. It has zero application outside of the world of y-ism. It floats.