If you intend to write a compendium, I would suggest trying to stress some of the aspects of rationality that perhaps weren't given as much time as they deserved in the Sequences. For example, recently in a comment on Effective Altruism forum, someone wrote a critique of the focus on the Bayes’ theorem component of rationality:

Bayesianism is not rationality. It's a particular mathematical model of rationality. I like to analogize it to propositional logic: it captures some important features of successful thinking, but it's clearly far short of the whole story.

We need much more sophisticated frameworks for analytical thinking. This is my favorite general purpose approach, which applies to mixed quant/qual evidence, and was developed by consideration of cognitive biases at the CIA:

https://www.cia.gov/library/center-for-the-study-of-intelligence/csi-publications/books-and-monographs/psychology-of-intelligence-analysis/art11.html

But of course this isn't rationality either. It's never been codified completely, and probably cannot be.

Honestly, I was struck more by the similarities than differences between The Sequences and the CIA's guide to qualitative analysis of competing hypotheses. However, they do put more stress on things like competing hypotheses and "diagnostic value". I'm not sure if the Sequences even mention a process for determining how sensitive conclusions are to faulty data, but it definitely should. I can't find the name for it at the moment, (and the CIA's guide doesn't name it either) but I know there is a mathematical technique for complex functions like climate models where researchers will test the sensitivity of the model to assumptions by varying the inputs and looking at whether the models output is invariant.

A desire for a more evidence-based focus was voiced here, although I think we’re not all that far off the mark when you take a broad view. It’s mostly a matter of emphasizing a few key points and playing down a few others that we’ve over-emphasized.