I think client side modification is probably better (albeit inefficient) engineering anyway.
They posted a Show HN here a few weeks ago, which is how I learned about them. Highly recommended!
Example: https://hw.leftium.com/#/item/36200884
Can even show just root replies to a comment: https://hw.leftium.com/#/item/36201108
Each page has a link to the original HN page.
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My app doesn't show the default HN feed; it shows the list of all items that have hit the front page in reverse chronological order (like https://hckrnews.com/).
If you want the default feed, use https://hackerwebapp.com/ (I forked my app from this app)