DL's selective cooperation with CI is frustrating. If I want to go MSP-TPE connecting in LAX or SFO to CI, CI's own booking engine and ITA usually both suggest Sun Country for the domestic segments! The same routing on DL.dumb often has combined pricing higher than separate R/Ts for the domestic and international portions on the respective ST carriers. Also, is there any way to book CI PE under a DL flight number?