Let's face it, there is absolutely no way to reliably generate IVs for posts from some categories. Those include /materials/*, /mag/*, /courses/*, /special/* and other highly dynamic types of posts:

https://arzamas.academy/mag/446-arch
https://arzamas.academy/materials/1318
https://arzamas.academy/university/units/4
https://arzamas.academy/courses/5

Their authors basically create an interactive mini app for each other post and there is no way to identify them because they use unique markup every time. Even similar relatively simple blocks are often made differently.

There are other categories where posts are simpler and more consistent:

- Radio announcements: https://arzamas.academy/radio/announcements
- Events (at least those without maps): https://arzamas.academy/offline
- Daily micro posts: https://arzamas.academy/micro
- The "East and West" course: https://arzamas.academy/uni/eastwest

I believe it's better to generate IVs only for these categories and ignore the others.