> There's an entire parallel scientific corpus most western researches never see.

Most of the scientific corpus (I would wager >99%) is not read by anyone. At least in physics, all the stuff you want to read is in english, in the journals that your global community cares about. I'm not sure (in physics) that you're ever going to find anything useful here. From my brief look around I see a lot of junk (similar to the arXiv).

My usual method for keeping up to date on the arXiv is to use their API (rss feed with search query in url) for terms I care about, but usually on click on papers by groups I value. Unless I see papers for those groups on chinarxiv.org (and I didn't find any from the good Chinese groups), I don't think it's worth it.

Anyway, keen to hear if anyone else finds something useful here.