Yesterday I was at T-Dose, a annual Dutch opensource event. I had a talk about NethServer and one of the people in the room was a Dutch developer of an opensource java based printing application that gives you a lot more control about the use of your printers. It also allows for payed options for printing. This is especially useful in schools where students have to pay for printing.
But it also allows to avoid printing: By giving options to edit prior to printing and send a PDF instead of printing on paper.
The project website is at https://www.savapage.org/
I understood that it is developed as a (java) layer on top of CUPS. We already have CUPS as a module (printserver module) and java is already available if you choose to use WebTop as collaboration application.
Therefor I think it shouldn’t be too hard to add this as a module (or extra addon for the printserver module)
Some more info about savapage:
Code abailable on gitlab.com: https://gitlab.com/savapage
Savapage FAQ: https://wiki.savapage.org/doku.php?id=savapage:faq