Data point on changing to an open-jaw. As expected, despite R inventory being available and the change being allowed, the system reprices to the next fare class. My change from LAX-JRO to LAX-ZNZ, JRO-LAX, was ~$2,800 more. Considering my original ticket was $1,600 (JFK-KBP) I decided to keep my roundtrip intact. Glad I at least attempted the change though.