You only replaced ONE side?!?!?!?

By alignment "OK" this means what? BMW says "alignment OK"? Not that I think it is the alignment but just getting a "BMW Alignment" will usually mean your tire life will be suboptimal. They are required to check the alignment when the LCA or bush is replaced, BTW....

Once you modify the suspension you are on your own. I am 100% behind this- perfectly reasonable for BMW to do this.

Replace the other side lower control arm bushing AND look at the sway part end links.

And while I know you dont like people commenting on aspects of your post that might not be of concern to YOU, these 'conversations' can help others.