Actually not true. There is body contact in competitive smooth. While in a social setting it might be uncomfortable as well as when it is first taught it is easier to teach when the could has more room between them since they are likely to look at the floor etc, when you get into a competitive setting, it is actually a part of it. As a teacher, every time I do a checkout we have to dance a freestyle to show we can lead and follow the steps and the very first check out I did we got penalized for not having body contact in the freestyle and the first checkout was for a social syllabus. On top of which closed hold in smooth should be no different than closed hold in standard
I agree that the closed hold in smooth, for best dancing, should be no different from the closed hold in standard for best dancing. I don't necessarily agree that involves body contact. A few years ago a recent world professional standard champ was teaching keeping a "cushion of air" between the bodies, which suggests that without the explicit rules requiring body contact in standard, there would be a school that did not consider it very important. The fact that your particular studio requires it - or at least desires it - from their instructors does not mean that all studios do the same.
In addition, last I checked, there was no written rule that you have to maintain body contact in competition in smooth, whereas in English ballroom, there is - I've even heard violations pointed out on the microphone by the chairman of judges.
The lack of an explicit rule means that it's more appropriate, for smooth, to start with learning a good frame and good lead and follow. Eventually if you are doing everything right, the body contact may just happen, without ever having to work on it.
and yes breaking apart characterizes the style especially in silver and gold. There is a reason why most bronze syllabi have few apart steps in them, because during that time you spend in bronze you should be improving your closed hold
I'd agree that the distinguishing characteristic of gold level American smooth is open work. However, that's not true for the silver level, for which the distinguishing characteristic is continuity style movement. Too many competitors these days fail to properly learn continuity style movement because they are in too much of a rush to get to the open work.