I hope to build my own thing, so content/categories that would help me would be, for example:
 Discussion on the physics and math of what we are doing.
 Discussion on how to build CAD models and how to run simulation on those models.
 How to manufacture the things we think of.
 Inspiration in seeing what other people have done or are doing, in patents, literature, and so on.
 Probably a section that specifically discusses the things we (the makers) are trying to solve now? But then there is perhaps a risk that discussions that perhaps should go in - goes in here.
Because I saw this a lot in the old forum, also:
 A section for “blue sky thinking” / brainstorming / open-minded thinking.
You can create categories and also subcategories within those categories.
Also you can enable tags, I think it requires a plugin or something? You could for example tag all content about a particular company. Clicking on the tag then leads you to that content. That way you don’t need to potentially create hundreds of subcategories or rely only on text searches.