That's because BA wanted at least double miles for multi partners award instead of using 1 partner.

CX first doesnt come along easier when book in short notice. So I was able to secured LAX-HKG-KUL on the date I wanted. And later, found SIN-HKG-LAX.

SAN-LAX was an add-on after the BA chances their program. Only cost me 9000 avois points and $5 to redeem the roundtrip ticket. Save me a drive to LAX since I'm based in SAN.