What would it take for China to sign the Rome Statute? China has played a key role in developing the ICC pretty much since it started and has recently been talking a lot about upholding international law, yet still refuses to officially sign the Rome Statute. With the increasing role China plays in the international community, I think its only a matter of time until they do, it would be great for the PR of the country. Though I do get it if they are afraid that the ICC will go after the fake claims of Xinjiang and other "war crimes" China has committed due to political bias of the court, which is what I'm guessing has been preventing them from signing for the past 3+ decades.
Makes sense, and that just reminded me about the new international court they plan to setup in Hong Kong to settle disputes between global south nations. Just checked and its called International Organization for Mediation (IOMed): https://www.international-mediation.org/