Hello Daniel,
Yes you can create subdirectories under the main VCRM folder. I name my folders after the SPP name and unpack the iso in these subdirs. The only disadvantage to this is that you get duplicate files because SPP's have files that exist on several versions. You will also see this in the logfile but technicaly all works just fine. So all is fine and you easily cleanup old SPP's.
Have a great new year...(here we just went to the new year in the Netherlands)
Kind regards,
Andrew