[inferiorhuman]

  now they had access points to check the pressure.

This is such a mixed blessing. It's great for diagnostic work, but it's also one more place for things to leak over time. Cars can deal with leaks (and are expected to leak by design) but they've also got a couple pounds of refrigerant if we're talking R134a. A fridge has like 40 grams (which makes the explosion hazard stickers on the R600a fridges kinda funny). Were it me, I'd be very wary of accepting sealed system work under warranty.

  Also, the LG parts all had copper brazing points, so the tech never
  had to work with aluminum/steel directly.

That's interesting. I wonder how the mix of metals bodes for longevity.

  Finally, I wonder, after your initial comment, if there was just a
  problem with the refrigerant charge, which was causing your fan to
  ice over as a byproduct because it was slightly under/overcharged
  from the factory.

To be clear the whole evap was icing over. But the fan is, by necessity, quite close. I'm inclined to think it was filled properly at the factory because overall the build quality was leaps and bounds ahead of Whirlpool (and Frigidaire). It wouldn't take much to convince me that there was some sort of electronic component failure as one thermistor was already out of spec.

With the LG I was a renter, so I was willing to push things along with LG and do as much diagnostic work as possible. But at the end of the day I didn't really want to dig into fixing anything myself because the fridge simply wasn't mine. I also didn't have room for a second "project" fridge. The landlady wasn't out anything because it was covered under the extended warranty (my initial call was a year + 1 day after the purchase) and LG bought it back for full retail price.