Can a single report in DRM be directed to multiple printers, but specific trays on each those printers?
Yes. In order to accomplish this you would create two DRM report IDs. You would start by creating the first one and point it to the first printer (white paper) and then duplicate the report ID, using the duplicate function right in DRM, and point it to the second printer. This is how you would print any report multiple times to multiple locations. You can also print one copy and maybe email or print to file, another copy. You can use this same type of setup to accomplish this as well (Report ID # 1 has a print destination to printer and Report ID #2 has a print destination to file).
If you are printing POs out of DRM, you need to add a stored proc to your Crystal/SRSS report. The proc will update the printing status to mimic what printing the PO straight out of GP would normally do. We have a KB on our website with an example: How to print a PO using DRM and update the status. You or your VAR would be responsible for creating the stored proc for your custom report.