In a video by @[email protected], Alec goes into a deep dive into the simplicity of his particular model, its shortcomings and variety of data logging tests in an attempt to fix them.
TL,DW: Very simple, cheap and ingenious design, with one compressor loop between the fridge and freezer in series. However, its temperature sensor is wonky and so the fridge is more affected by how long the compressor operates than the actual temperature itself. There is a signficant temperature differential between the top and bottom, fans on the exterior or interior could help but with the faulty sensor only made matters worse. With the controller replaced with a proper temp control unit the fridge functioned much better.
To be fair to portable AC, they are inefficient but functional, and you can improve their efficiency with a variety of methods such as insulating the tubes.