as a Chinese and an expert in expired domains ( sorry dont banish me lol), i will clear you a bit, if you found sth useful, then glad I can help
1) when you found Japanese anchors, 99.9% chance its spammed, so dont use all domains with Japanese anchors, you will not regret this(but i surely encounter some non spammed ones), and I will tell you another thing, some "spammed" Japanese PBN domains can be reuse again, because Google seems pretty forgotten about some domains, or just they forgot to renewal, anyway, better leave away, nothing lose
2) when you found some Chinese anchors, 50% chance, its Clean, 50% chance, it is related to Games hack/online casinos, so the answer? Yeah, leave away, you may lose some gems in this way, but better not take the risks
3) Japanese use Google.co.jp, thats why you see so many, or even tons of Japanese PBNs, because it worked in the past or now, but you may never meet a Chinese PBN, because thats no sense to do that, we use baidu.com, means, its completely different from Google, PBN trck doesnt work(work but not in the same way like English world)
4) above 3, i cant recon more things
So hope these tiny things could help u a bit !
terry