vmc and sensitive volumes in G3/G4

Hi, I am in the process of optimizing my VMC application and have a question about the handling of sensitive detectors and scoring in general. From the VMC examples (e.g. E03) it is assumed that the selection is done within the TVirtualMCApplication::Stepping (possibly through invoking a MySensitiveDetector::ProcessHits method which contains for example a gMC->GetVolId and comparing with volumes ids of interest). However, looking at the output of BuildPhysics we can see for E03 that the number of sensitive detectors is the same as the number of logical volumes.

     GEANT4 Geometry statistics:
               6 logical volumes
               5 physical volumes
              13 materials
               9 user limits
               6 sensitive detectors
**********************************************

phot: for gamma SubType= 12

I was wandering what is the impact on this on performance. Is it correct to assume that ProcessHits is called for all defined sensitive detectors as in the vanilla G4, or is it avoided somehow within the TGeant4 by doing something equivalent to (G4 code inside TGeant4)

myLogicalVolume->SetSensitiveDetector(nullptr)

If it is not done, is there a way to deactivate sensitive volumes through TGeant4 interface?

Thanks,
filimon