If you want a smoke ring, get a stick burner or an FEC.
But seriously, the electrics can't really produce a smoke ring since the wood doesn't burn, it smolders. Some people have tried to add charcoal briquettes with mixed results. But a smoke ring only makes things look pretty. It doesn't do anything to enhance flavor.
When I had my SM020, I initially tried to get a smoke ring, but gave up. Now that I have an FEC and can produce one, I could really care less if I get one or not.