A question on scintillation handling

Dear all,
I am going through example E06 of geant4_vmc tarball. Trying to simulate a lead/scint fiber calorimeter (now moving to the optical part as the energy deposition seems correct according to data comparison) I have an initial question.
In the Ex06DetectorConstruction.cxx file in the ConstructOpProperties method there are some comments like "Added (for Geant3)". Since I do not know to which set of properties they apply (only for efficiency?), my question is, are these only used by G3 back-end, in the sense that G4 handles them differently? If yes, by which mechanism? I see that in the provided g4config.in file the scintillation is deactivated. In my use-case should I then enable this (or simply delete the lines) and provide all the G3 information that is in the ConstructOpProperties in a G4 format in the g4config file or are the fields under "Added (for Geant3)" also applicable for G4 (I am obviously interested for the yield/MeV and the slow/fast component arrays and ratio/settings). To summarize, if I just remove the line about disabling scintillation in the g4.in file, will scintillation work correctly for both G3 _and G4 with something similar to the example code (provided ofcourse that I use the proper values for my scintillating material where applicable...)? A more advanced but related question is whether there is some provision for birk's law under G3 or G4. Any provision/experience on this? Thanks,
filimon