I don't think adomatic wants to go out twice. Just wants to use the lounge first to relax, then go out on a transit tour and come back. Recently I haven't had much problems with long waits at immigration at ICN. A year or so ago I was often stuck in some long waits but none recently. Early mornings entering Korea and early evening leaving Korea seemed to be the worst times. Leaving later in the morning and coming back in the afternoon there shouldn't be any significant immigration delays unless you happen to be unlucky.