Great article, Robert. I really enjoyed it and appreciated what you shared about your experiments.
Are you aware that Medium does have a “tips” line where readers can share stories they feel deserve to be curated? You can email email@example.com to share recommendations. I don’t think emailing them is very effective, but it is one avenue.
I also think it would be easy for Medium to use claps as a proxy for a “recommend” button. Articles that organically get a lot of claps and a high read rate should be auto-pushed to curators. I’ve seen a couple instances that have led me to believe that the curation process actually may work like that (articles getting curated after getting lots of natural traffic), but if Medium isn’t yet employing that method, they definitely should consider it.