Restarting membership year
 

Several years ago, I joined MarcoPolo Club and accumulated about 10,000 miles flying around Asia but have not added anything subsequently—these miles are due to expire next March. More recently I have begun a lot of flying and have attained OW Emerald status on AA and BA. For various reasons (including more focus on Asia, my wife’s BA status, etc), I have begun thinking that it makes more sense switching my future accumulations from BA to CX. Ideally, I would like to start a new CX membership year now. However, the old membership year starts in March. But I don’t want to have only two months (Jan-Feb) to try to reach CX status. Thus it seems that crediting any miles to CX over the next couple of months would be a waste unless I could start a new membership year right away. Is this a correct interpretation? Suggestions?

If you are able to accumulate 30,000 miles between now and the end of the current membership year then it wouldn't be a waste since after reaching 30,000 your account will be reset anyway. From there you will need to get another 60,000 before reaching gold, and then another 120,000 for diamond.

One thing MPO won't and can't do is close your membership year early.

You may want to consider opening a new AM account and hope CX will convert it to a MPO membership without charging a fee based on your extensive travel. But I see no benefit in doing that against keeping your current account.