Since you’re asking specifically about RSS, I recommend FreshRSS and RSS-Bridge. FreshRSS can filter by keyword to mark things as read automatically, and RSS-Bridge Can help with making RSS feeds for sites that don’t have them. FreshRSS can do that, too, but only with XPath. RSS-Bridge has a few more tricks. Also, I recommend checking out Wallabag, a pocket alternative that can output your saved articles as RSS feeds.