Some of the tests apply to both boards, so until a year has passed the marks you got for the tests you already took will stand - whether that's good or bad for your second option, WSOp in this case, I don't know. However, I am the other way round - I took Board B, and the debriefing officer suggested that since I got good marks I come back and do the Board A tests, and they'll just tack those scores onto the tests I already took to get a clearer picture. So what I'm saying is: consistency of message seems to be an issue between OASC and your AFCO.