I did not like your review much. It looks like it was cobbled together hurriedly, without much thought and without proper instrumentation. It was far too long and you mumble a lot, making it hard for the listener to understand you.
Especially if your review is a negative one, you should test the meter with known values of inductance, resistance and capacitance, to back-up your findings. Any electronic shop will have a range of them at an affordable price.
The method of working out inductance with a resistor and a function generator is fine for ballpark figures, but is not very convincing to test the accuracy of an LCR meter.
Ideally, a high-end LCR meter should be used for a fair comparison.
You didn't mention that there are 5 adjustable pots on those PCBs, which can be tweaked to increase accuracy. UNI-T has a high volume production and at that price point, they don't spend much time adjusting the meters beyond their published tolerances.
I look forward to a follow-up review with the help of a decent LCR meter, if you ever get one.