Interesting work! I admit I just skimmed the post quickly, so sorry if it's been mentioned already, but: is there a way for users to report/flag bad suggestions? On YouTube, for example, there's a similar list of "bubbles" for topics and I keep getting suggestions of topics I'm not interested in because I care for adjacent topics (e.g. for one soccer team because I follow another one). I'd love to be able to long-press the bubble and then get a report/flag option in a pop-up menu, for instance.