@bentael After some pause, I think I'm ready to work on custom importer. After some investigation I have found, that Importer works with classic/basic entities. Even If I will create custom importer, for example nodebb-plugin-import-ipboard-very-custom, import plugin will use only designed methods (I will be able to import additional fields) like: setup, getPaginatedUsers, getPaginatedCategories, getPaginatedTopics, getPaginatedPosts, and several utility methods like logging, testRun, etc.

My question: as author of importer, what do you recommend to do if I want to import additional entities? (Example: awards)

What I want to accomplish after import: Import of standard data: topics, categories, posts, users - It's simple and clear Import custom user fields without altering User document for future plugin use Import additional entity - Awards for future plugin use Import additional entity - Points(like reputation, but isn't part of user table) for future plugin use