How to make CUPS client send more than one job at once?

[Jeff Benjamin]

I have a MacOSX workstation (the CUPS client) that is sending a print job to a MacOSX print server (the CUPS server).  On the server I am using a backend returning code 3 to cause the job to hold.  In a separate process on the server the job gets analyzed and may be held for user intervention before it gets released to some other real print queue with a normal backend.

The problem is the CUPS client will send the first job and sense that it is still "Printing" when the job is held.  If more jobs get queued up the CUPS client will not send them over to the server until the first one has finished.  I need to make the workstation send whatever jobs are printed.  I don't want the workstation to act like a print server.  This setup is using IPP and Bonjour only, in case it matters.

Is there any way to accomplish that on the workstation (CUPS client) side?

Thanks,
Jeff