Mesh selection - mesh highlight

Hello forum,

=> on Opencascade 7.3.0 - MSVC2015.

I implemented mesh selection in an AIS_InteractiveContext using 

occMeshContext->Activate(meshVS,theMode)

in which meshVS is a MeshVS_Mesh and theMode is one among  MeshVS_SelectionModeFlags.

The presentation builder was added in this way:

occHandle(MeshVS_MeshPrsBuilder) aBuilder = new MeshVS_MeshPrsBuilder(aMesh);
aMesh->AddBuilder(aBuilder,true);

(treat as highlighter true).

Questions:

1) The default dynamic highlight mode for for a face element, in case of a surface mesh, is shown in the first picture (mesh2D.png),

toghether with the selection highlight: an ugly shrinked wireframe view. The same for the second picture (mesh3D.png),

dealing with a volume mesh, How can I change these defaults modes (selection and dynamic highlight)

2) The use of the flang MeshVS_SMS_Node does not activate the selection/highlght mechanism for mesh points.

How can this mechanism be activated?

I didn't study the code by I suspect that something a bit complicated than issuing a simple occMeshContext->Activate(meshVS,MeshVS_SMS_Node)

This serms to be not enough for activating the mechanisms for nodes, since the mesh presentation is element based. Any idea?

Thank you in advance

Giovanni