Try routing to see if there are any availability on JL from west coast to Beijing. It will most likely route through HND/NRT, where you can possibly force in a 23 hr layover of some sorts. Beijing will be your stopover. Then, from PEK to KUL on MH.

This seems feasible if you're flexible with dates and are willing to play around to piece together an itinerary. Overall, looks like oneworld will be your best option (and you seem to be set on that).

For a revenue ticket, try openjaws like XXX-PEK on NH or JL//KUL-XXX, and then just separately buying a PEK-KUL or using BA avios to get that short(ish) segment. NH seems to usually have good OJ fares from west coast to KUL in my past searches.


Also, PEK has 144 hr visa free