Agreed on all points. Regarding para 2, I am assuming that there is something like a CMS in place that can pluck docfiles from version control and massage them

Agreed on all points. Regarding para 2, I am assuming that there is something like a CMS in place that can pluck docfiles from version control and massage them and insert them into an outline/ToC. (And then propagate changes back to version control.) Regarding para 3, there's now many GUI tools for working with Mermaid et al. But are any of them properly integrated into documentation systems ?