why would an infinite number of states, none of them valuable in themselves, be valuable collectively?

I made a partial answer that question above when I wrote the following. A longer answer is on my list of things to write.

One principle or intuition that leads me to believe that is that the proper way to determine the desirability or the rightness of an event is to examine the effects of the event. If we are applying the principle or intuition uniformly, we are naturally led to an examination of the effects of the effects. And so on indefinitely.

A slightly humorous summary: it is not the events collectively that are important; it is the last event of the infinite chain.

My reply to that is that the existence of such a process is no argument for using anything but the most correct or reliable moral framework as the starting material of the iterative process, and again collective or coherent human volition or the moral intuitions of almost any human is not it.

why would you want to implement a system that will ignore any future such argument?

By “such argument” you refer to things like my moral intuitions. Again I have little respect for the moral intuitions of myself or most other humans.

I was exposed to Garcia’s first book in 1978, and made an extremely close reading of his third book shortly after it came out in 1991. Both books are book-length descriptions of what is essentially GSZ (without the vocabulary of decision theory, transhumanist futurism or Eliezer’s writings). GSZ is tightly integrated with my thinking on just about every issues that touches on morality. I have used it to make decisions and to understand the “moral environment” every single day since 1992. It seems to me that the normal human mind always needs some moral framework with which to interpret the events and the political, legal and moral arguments one comes across. Since 1992 GSZ has been mine. (The fact that it is so different from others with whom I interact has proved a significant social handicap, BTW.) My understanding of the ramifications of GSZ is of course imperfect, but it is easily sufficient to discredit and impeach in my mind Eliezer’s proposal for the source of moral information.

Also, the idea that almost any human has easy access to correct moral information without having done a great deal of work learning things like math, logic, the art of rationality and general science is very widespread in our culture IMHO because it has assisted the careers and the status of whole occupational groups whose marketable skill is to influence easy moral intuitions about strategic subjects for social, legal, political or economic ends — and not because the idea can stand up to any serious scrutiny by sufficiently rational agents.

Note, too, that the idea of an agent-indifferent goal system concerned with the whole universe has been widely discussed since Teilhard’s publications of the 1940s or 50s.

Also, you said:

The extent of my special pleading is to prefer a goal system of constant improvement (of intelligence and of the model of reality) over one of “we might as well eat our own brains because we won’t be needing them.” Surely that is a choice we can all agree on.

I’m curious as to why you allow yourself to take this principle from your moral framework, but not other content.