Its been a long while since I used it and have no experience of using other render cows but your description of how it works matches my expectation of how a queue should work. When I print a document to a print queue its rendered to an intermediate format file which is queued on the print server until the document is printed and then deleted. T'he fact the Poser queue manager stores the intermediate file as a scene file is a quirk of design not intent that anyone would use it for other purposes. Maybe my expectation is wrong but I think you're looking to enhance its operation rather than it needs to be fixed.