On 17 Nov 2023, at 09:23, Ran Regev via SG21 <sg21@lists.isocpp.org> wrote:

Can you please point to documents, articles, forums, etc. that show this growing sentiment?

Daniel Ruoso gave a great talk about this at this year's C++Now conference, titled "The Challenges of Implementing C++ Header Units": https://www.youtube.com/watch?v=_LGR0U5Opdg 

Highly recommended.

He also wrote a paper called "Importable Headers are Not Universally Implementable": https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2023/p2898r0.pdf 

This revision is - according to my understanding - obsoleted by the discussion we had in Varna. They were implementable before, but not to the extent that e.g. Bloomberg requires.