Here's a small, player-only (for performance reasons, mainly, though figuring out the AI logic would probably be a bit messy since we don't know how the marriage logic works...) improvement that should be part of the next version when you get it (not terribly soon, as we have a bunch of things we want to include in it that aren't close to done).
It is now possible for the Emperor of China (and the dynastic ancestor of a female member of the imperial dynasty, e.g. a father towards his daughter) to selectively make Chinese "princesses" available for marriage/betrothal outside the Request Imperial Marriage Grace interaction for a short while (until the next trait update, which happens roughly once per year unless Emperor ruler of China changes; it shouldn't cause any marriages or betrothals to break, but there's a small risk of an update being poorly timed and re-applying the trait in the middle of a marriage/betrothal offer (it's the least bad way to do things behind the scenes, I'm afraid)). This will cost you and her some prestige (currently 500 each) and might hurt the Mandate of the Emperor of China (it'll subtract a set amount from one of the three categories that are being checked behind the scenes the next time it is checked, which could be enough to cause a Mandate drop, but it's not guaranteed to cause a Mandate drop), but if you really need to secure an alliance/NAP (or you're a vassal and you feel like hurting your own dynasty's rule just because you're feeling contrary...) it could be a good idea.
There are also two new bloodlines around in Indonesia (though only one of them will be around at any time because the male line goes extinct), one for the Srivijaya dynasty and one for the Saliendra dynasty (the exact starting point for this one is subject to change as it might make sense to put it one or more generations earlier as the history of the region gets improved). Both of them convey the same benefits (I'm aware the text looks weird, but it is hopefully readable).
AI rulers with these bloodlines will also generally be more interested in waging war for tributaries (permanent if JD CBs are active, non-permanent if not) than other rulers, and Chinese Imperial emperors have also been made quite a bit more interested in doing that, provided the target doesn't hold land in China and that the attacker isn't part of the Genghis Khan bloodline (as Mongols that rule China should be a bit more interested in conquering stuff than just making tributaries).
It is now possible for the Emperor of China (and the dynastic ancestor of a female member of the imperial dynasty, e.g. a father towards his daughter) to selectively make Chinese "princesses" available for marriage/betrothal outside the Request Imperial Marriage Grace interaction for a short while (until the next trait update, which happens roughly once per year unless Emperor ruler of China changes; it shouldn't cause any marriages or betrothals to break, but there's a small risk of an update being poorly timed and re-applying the trait in the middle of a marriage/betrothal offer (it's the least bad way to do things behind the scenes, I'm afraid)). This will cost you and her some prestige (currently 500 each) and might hurt the Mandate of the Emperor of China (it'll subtract a set amount from one of the three categories that are being checked behind the scenes the next time it is checked, which could be enough to cause a Mandate drop, but it's not guaranteed to cause a Mandate drop), but if you really need to secure an alliance/NAP (or you're a vassal and you feel like hurting your own dynasty's rule just because you're feeling contrary...) it could be a good idea.
There are also two new bloodlines around in Indonesia (though only one of them will be around at any time because the male line goes extinct), one for the Srivijaya dynasty and one for the Saliendra dynasty (the exact starting point for this one is subject to change as it might make sense to put it one or more generations earlier as the history of the region gets improved). Both of them convey the same benefits (I'm aware the text looks weird, but it is hopefully readable).
AI rulers with these bloodlines will also generally be more interested in waging war for tributaries (permanent if JD CBs are active, non-permanent if not) than other rulers, and Chinese Imperial emperors have also been made quite a bit more interested in doing that, provided the target doesn't hold land in China and that the attacker isn't part of the Genghis Khan bloodline (as Mongols that rule China should be a bit more interested in conquering stuff than just making tributaries).