All fair enough, but I'm really looking at the beginner spending $149 on a guitar kit, not someone applying for a guitar technician's job for The Rolling Stones :-)

"The real issue with flat-topped frets is that they reduce the active string length slightly, back to wards the bridge, making accurate intonation across the whole fretboard harder to achieve."
This point has been raised made many times, but I still question the validity. A guitar is not like a piano, where the player has no control or influence over the pitch. Slight errors in the positioning of the guitarist's finger are surely going to be "swamp" any errors introduced by by the shape of the fret top. This would be particularly so with your average punter with his sub-$200 kit.


"it really is better to level the frets first then re-crown them."
Not if you're using a sub-$10 crowning file though. Yes, you can easily spend far more than the kit cost on tools, but I question whether for most people it would make any worthwhile difference.

"And using a notched straight edge to get the fingerboard flat first (which is very achievable unless the fingerboard itself isn't level any more and has twisted) is better than using a straight edge on the top of the frets, as the reason you are doing a fret level in the first place is that the frets aren't all the same height."

Sorry; I don't really understand what you mean. This highlights what I alluded to earlier; somebody with a lot of experience and who has possibly made several guitars will no doubt understand, but your first-timer won't.
Is a "notched straight edge" like a ruler with cutouts that straddle the frets? That does sound like an addition to the "The tools cost more than the guitar" list.
The "successive approximation" technique I described (repeating an adjustment a number of times getting smaller errors each time) will always work. That was basically how Elon Musk managed to get his rockets so cheap. (Rather than trying to predict what might go wrong, you pack them full of telemetry to record everything that happens and just let them blow up :-)