They have to scrape the site in the background to work. While this is doable, any such client will need to follow the HN bot policy which limits the scrapping s

They have to scrape the site in the background to work. While this is doable, any such client will need to follow the HN bot policy which limits the scrapping speed. Another issue is browser only client. If HN has set proper cors (I didn't check if it is the case), then you cannot build a web client through scrapping without proxy.