In the article below we learn that we have to "jump through hoops" to print documents with custom margins (such as checks). We find this to be unacceptable. Please enhance the document routing agent so that it can handle documents with custom margins (just like any other document).
Documents that require custom margins
When the Document Routing Agent runs as a Windows service, document reports, such as checks, that require custom margins can't be printed directly to network printers. Instead, the Document Routing Agent automatically routes those document to a target folder. New configuration properties in the application's Settings dialog box let you define the target location for document reports that require custom margins.
When the Document Routing Agent runs as a desktop application, it continues to take advantage of Adobe Reader to spool the document to the shared printer device that is selected in Microsoft Dynamics 365 for Finance and Operations, Enterprise edition. To handle scenarios where documents that have custom margins must be printed, we recommend that you install the Document Routing Agent in multiple locations. Then install the printers that will handle those documents only on the Document Routing Agents that will run in desktop application mode. Alternatively, use a post-execution process to pick up the files in the target directory and direct them in the appropriate manner.
Source: Run the Document Routing Agent as a Windows service (as of 9/13/2017)