Hi Tudor, there is a new function for edge curves in the next beta: edge.getIsTangentEdge() , it should help for making a script that would hide things like you want.

The way you will be able to use it is like this:

 var breps = moi.geometryDatabase.getObjects().getBReps();
 for ( var i = 0; i < breps.length; ++i )
 {
	var edges = breps[i].getEdges();
	for ( var j = 0; j < edges.length; ++j )
	{
		if ( edges[j].getIsTangentEdge() )
			edges[j].hidden = true;
	}
 }

- Michael