You may be already aware of this but the BuildPackFile and EditPackFile functions are not working with SRTT VPP_PC files (r130 I think, might want to add a -v version switch).
ThomasJepp.SaintsRow.BuildPackfile.exe srtt "soundboot.vpp_pc" "Temp"
Building Temp using data from soundboot.vpp_pc.
Unhandled Exception: System.NotImplementedException: The method or operation is not implemented.
at ThomasJepp.SaintsRow.BuildPackfile.Program.Main(String[] args)
ThomasJepp.SaintsRow.BuildPackfile.exe srtt "soundboot.vpp_pc" "Temp"
Building Temp using data from soundboot.vpp_pc.
Unhandled Exception: System.NotImplementedException: The method or operation is not implemented.
at ThomasJepp.SaintsRow.BuildPackfile.Program.Main(String[] args)