Regarding the license issue, I had a closer look at the conditions.
The way we plan to build our pdf generation stack is to have a server providing pdf generation as a service to the rest of our stack (allowing for pdf rendering in order to attach it to a mail for example).
As such, the current plan is to call this pdf generation service (through RMI) and then give it everything it needs to run. In the current case, I think it means calling render(java.io.InputStreamReader isr,
Does it qualify us for the volume license ?