Related to what others (e.g., harfe) have already commented, it seems a sad truth that many domain experts reason poorly as soon as you go slightly outside the prevalent framings of their domain. For instance, someone may have a good track record improving current-day ML systems but lack interest in forecasting anything that's several years in the future. Or they may not be thinking about questions like whether particular trends break around the time ML systems become situationally aware of being in "training" (because we're far away from this, so it has never happened thus far.)  If domain-experts had a burning desire to connect their expertise to "What's important for the course of the future of humanity?" and get things right,  get to the truth, they'd already be participating more in EA discourse. Which isn't to say that everyone with an interest in these topics would endorse the conclusions prevalent within EA – but at least they'd be familiar with these conclusions and the arguments. The fact that they're only domain experts, and not also existing contributors to EA discourse, is often evidence that they on some level lack interest in the questions at hand. (In practice, this often manifests itself as them saying stupid things when they get dragged into a discussion, but more fundamentally, the reason for this is because they massively underestimate the depth behind EA thinking simply because it's outside their plate and because they lack a burning desire to think through big-picture questions.) 

FWIW, I think Open Phil often commissioned domain experts to review their reports. (They probably tried to select experts who are interested enough in EA thinking to engage with it carefully, so this creates a selection effect, which you could argue introduces a bias. But the counterargument is that it's no use commissioning experts who you expect will misrepresent your work when they review it. So you want to select experts who've previously engaged intelligently with shorter version of the argument – and that sadly disqualifies a significant portion of narrow-domain experts.)  

Thanks for writing this, this is also something that's been on my mind with some degree of uncertainty.

My confidence for a lot of these reports would increase if I could see the peer review comments and responses or if otherwise the research (in parts or in full) was published in a peer reviewed academic journal. I know a lot of Open Phil reports commission external peer review and if I recall correct the climate change report was also peer reviewed. At the same time some of the comments in that thread implied reviewers had a lot of disagreements and it's hard to say how much of the feedback was responded to or not. To be clear, you don't have to agree with every peer review comment but seeing the responses would increase my confidence.

I'm still left with the impression that most work within EA isn't externally reviewed.

I wonder if some of the recent public award prizes, like Open Phil's cause prioritization one and GiveWell's change our minds somewhat fit here. More for Open Phil but I never found or got a sense of how entries were assessed or ranked. What are the crteria? This me doubt how we assess and valued expertise and research rigor. 

I think Joe Carlsmith’s philosophy training added a lot to the work in that he was able to more carefully specify the assumptions and arguments for for power-seeking AI.

This is a skill that philosophers are particularly well-trained for. I agree that AI experience is important too and I would love to see someone with this kind of relevant experience commissioned to write a follow-up report. But one reason why this would be much more likely to go well is that Joe Carlsmith has helped to make the terms of the discussion clearer.

Being able to communicate across fields is one of the most important skills one can possess. Some professional roles are essentially just this, E.g. product manager in software. I don’t believe the best academics in a field are necessarily the best people to write a report that is designed to be accessible. The best maths teacher I had at school was not even a mathematician.