I guess I need to read more about OW. Can I just apply my AAdvantage # up front and accrue AA miles on CX flights? And then, if wanted, use those miles within OW to fly BA or another partner? The only airline my wife and I have been flying for years is Delta and I am only familiar with accruing DL miles to later use on a DL flight. I figured I was going to have to get AM miles through CX to use within OW.

Thank you