I finally got it! Ordered 4 pairs, at the end of October 2020. Quality looks quite good, I don't think that there's any issue with the product, it should work properly.
Very large connectors will take 4 awg and 0 awg cable. Compared to XT90 it is 4 times the size. I will happily order more now for parts and future. I have not tested them to see how well the anti-spark works.