Also, always good to see you and congrats on a post of yours getting to the front page.
Reading the history and economics pages, and searching for hopeful paths forward, I thought of the NASA-SpaceX partnership. Where it wasn't that the component technologies had never been tried, or weren't known, but that company and systems optimized for atypical objectives might find an order of magnitude to pick up, and maybe soon two.
The follow-up piece to this one is the Economics page, and this section in particular talks about what's likely necessary to have a good future in nuclear [1] (it's a collection of conclusions from expert groups on the topic, mostly focused on economics).
[1] https://whatisnuclear.com/economics.html#improving-modern-nu...
The MIT Future of Nuclear in a Carbon-Constrained World report is excellent [2].
[2] https://energy.mit.edu/research/future-nuclear-energy-carbon...
The "economics" essay underplays two important issues and elides a third. First, learning curves. You are reluctant to let go of "economies of scale", for which you seem to place, ahem, a thumb on the scale against "economies of mass production". What you miss is the dynamic nature of learning. If you produce two reactors of size X/2 rather than 1 reactor of size X, you get twice as much learning, and that learning compounds. C.f. wind turbines.
Second, nuclear has many more serious competitors than it used to. Geothermal and various storage technologies produce market-friendly energy at gigawatt scale, and capital is being deployed to improve them as fast as it can be absorbed.
Third (and related): all economies are political economies, and nuclear has the worst politics of any technology. To their enormous credit, nuclear advocates are finally taking this issue seriously, but they have so much work to do.
Unfortunately, these three issues feed into each other. The happy case—the one I'm rooting for—is that a 5-10 megawatt technology gets so much capital behind it that costs are brought down to "vaguely competitive with offshore wind", and that it becomes an important option with gigawatts deployed annually starting around 2030. Unfortunately, by that point we're going to have GWh-storage paired with solar that is either 1/10th that cost or twice as efficient as currently, or both. The path for nuclear is narrow and treacherous.
Any plans to publish a book?
After completing this, I thought geez I should just make this a book. It's a relatively fringe subject, but hey maybe it'd be a good use of a sabbatical or something.
There is a lot of investor interest in advanced nuclear reactors because of climate change, so it could be useful to make this info more broadly available.
The little bits of information - that are currently scattered across hundreds of impenetrable reports - might still be interesting to a regular person, and who knows, inspire someone to pick up the new research.