How do Chinese encoders (WiKi, CHDBits) compare to top tier encoders (DON, TayTO)?
Also how do the Chinese remuxes (HDChina) compare to other remuxes (Epsilon, FraMeSToR, KRaLiMaRKo)?

Most Chinese trackers encode with the same encode settings for just about every movie; this means they are not seeking to do the best encode, but the fastest. Top groups aim for the best transparency so encode is hard to distinguish from the source.

Remuxes are probably less of a difference but chapters are not named and have seen them get the sequencing wrong (wrong playlist). Also groups like you mentioned above, particularly FraMeSToR make Hybrid Remuxes, taking the best Audio and Video from different Blu-ray discs (from different regions) and combining them into something that's better than any single source.

yeah, almost all Chinese encoding teams don't pay that kind of attention to advanced encoding settings.
Though WiKi is better than CHD & MTeam, it's not that much of an improvement.
But you can expect that high quality compared to DON, TayTO only from TnP & MGs among Chinese encoding groups cause they have some awesome encoders.