@enkiv2 I think the way to do it probably ends up looking like this:
The pre-chewing server implements a hierarchy of where things come from. So, you have an e-mail hierarchy, an RSS hierarchy, a Fediverse hierarchy, a YouTube hierarchy, a Facebook hierarchy, whatever, really. APIs and screenscraping are used to construct the hierarchies and the feeds.
There's also views of this content, based on various heuristics. (The master Inbox is basically where things deemed important go.)