This article:
https://docs.safe.com/fme/html/FME_Server_Documentation/AdminGuide/Configuring-Datum-Shifts.htm
explains various methods of configuring FME to work with USA and Canadian grid shift files. However, the company I'm working for routinely works with both USA and Canadian data, so it's not practical to set this value for all of FME.
Rather than performing a manual CSMapReproject everywhere it's needed in the workspace, is it possible to define the grid shift file to be used just once for an entire workspace? It would be great if this was available as a setting under Workspace Parameters but there doesn't seem to be anything there....