What is the current policy for OW and AY? In April booked two tickets with AA since AA's booking system seems to choose the most expensive leg and apply it for the whole itinerary, which makes a trip with many legs VERY expensive ($4000 USD difference). The CI agent just merged my itineraries and the bags went all the way to final destination.

I've been thinking of doing the same with NRT-HEL-STO since NRT-STO can be very expensive sometimes, but booking NRT-HEL and HEL-STO is cheaper.