It's been pointed out that he's essentially searching for reasons that even a Paperclipper would preserve everything of value to us, rather than just putting himself in Clippy's place and really asking for the most efficient way to maximize paperclips.

I don't think that a paperclip maximiser would "preserve everything of value to us" in the first place. What I actually said at the beginning was:

TT: I figure a fair amount of modern heritable information (such as morals) will not be lost.

Not everything. Things are constantly being lost.

In particular, preserving the fine details of a civilization, let alone actual minds from it, is really too wasteful if your goal is to be prepared for a wide array of possible alien species.

What I said here was:

TT: it is a common drive for intelligent agents to make records of their pasts - so that they can predict the consequences of their actions in the future.

We do, in fact, have detailed information about how much our own civilisation is prepared to spend on preserving its own history. We preserve many things which are millions of years old - and which take up far more resources than a human. For example, see how this museum dinosaur dwarfs the humans in the foreground. We have many such exhibits - and we are still a planet-bound civilisation. Our descendants seem likely to have access to much greater resources - and so may devote a larger quantity of absolute resources to museums.

So: that's the basis of my estimate. What is the basis of your estimate?