My experience went on for ~6 months of soap opera, similar to what you're describing, where an authorized service provider would "fix" it, and then it would stop cooling within a week or two. Then LG, or the authorized center, would diagnose some other thing that hadn't been replaced. No actual leaks were ever found, which was the problem after they replaced the compressor (the first thing they replaced, but it was on the 2nd trip), and now they had access points to check the pressure.
With the bonus that in our particular case, we were paying for the "labor" and getting the parts under warranty, which means that in the end I paid ~$1000 for repairs and LG claimed to have provided ~$1200 worth of parts (which is bullshit because an aluminum evaporator coil doesn't cost $400 unless it has a 20x retail markup). So, when they sent a check, it covered our sunk costs. But I had a fridge with a brand new compressor, evaporator, and condenser, as well as an upgraded control board/etc. This is part of the reason I took a crack and just ran it without the Yoder loop.
So, a couple of points: some other companies fix yoder loop leaks by bypassing them and feeding factory-provided heating coils through the now vacant line.
Also, the LG parts all had copper brazing points, so the tech never had to work with aluminum/steel directly.
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.