The first trip I booked just after the current tool was created started with CBR-SYD-LAX-PDX.
CBR-SYD was an AA codeshare. SYD-LAX was the normal QF code. LAX-PDX was a QF coded AS flight.
Trip was ticketed with no problems.
No one noticed until about 10 days before departure when the AA contract office in BNE called me to tell me about flight time changes (all of which I already knew about).