I had a situation in Fll a few weeks ago. Traveling Fll-Dfw-Hkg-Bkk . I had separate Hkg-Bkk ticket with Cathay. Told agent to check luggage thru. Said he couldn't do it, because can only do it with One World carries. Told him Cx is One World. He said no. Agent next to him came over and said she would help. In 30 seconds I had all boarding passes and checked thru. Conversation with them...he was former UsAir. Not familiar with transpacific routings and rules. She usually worked Miami int!l check in and had no problems with my routings.
There are going to be issues with cross training for awhile. But would be nice if they would discuss it, rather than just say no.