I feel like you are conflating the requirements for two different use scenarios here. For participating in a discussion, Discourse-the-software provides UI tools that are intended to obviate the need for (visible) post numbers:
- For “orientation” within a discussion, the progress widget shows how many posts are in the topic, and approximately how far down the discussion one has progressed
- The software also automatically bookmarks your location in a discussion, so no need to note or memorize your location when moving on to another task.
- For posts that require more detailed context, you can reply directly to a specific post. The discussion remains chronological, but the context is linked. (You yourself have made good use of this feature in this very topic!)
- Quoting part of a post allows the same linking, but at a finer level of granularity.
Numbers-on-post-header are noise from this perspective because no one in an active Discourse-the-software discussion should need to refer to “post #3.” It your comment is directed at the person who made the post, reply to the post. If it is about a specific statement in a post, quote the post. The software will provide a visual annotation without adding the cognitive load of an abstract post number.
It sounds like you need to attach meta-data to the post after the discussion is completed. I’d expect that this could be done through a custom plugin, but I’ll let the tech types go into the details. Anything stored in the forum database via plugin should be eminently exportable.
You’ve used the phrase “from multiple perspectives” a couple of times, but have not defined it. I’m assuming that you mean “slice, dice and reorder” based on various criteria, including the above meta-data. This should be done by an outside tool after export, and should not need to have post numbers added to the Discourse-the-software UI.