Been doing this for years to visit EU + South America multiple times per year. It's a great deal and makes it easy to maintain status. Usually need to return to the same EU country otherwise the price will jump. I was even able to do it in J on the outbound once for a 50% premium or so. PM me if you need help getting something to work. There are lots of interesting possible combinations. The max stay is usually rather generous, and the stopovers in DL hubs are cheap or free.