Currently it is possible to set a network based resource connection on FME Server with a name using forbidden characters for an equivalent user parameter in FME Desktop.
For example, you can set a resource connection with the following name (not the display name), 05-700-FMESERVER, which will give $(05-700-FMESERVER) when browsing it for a folder connection in a workspace on FME Server. You can use this key to call the connection.
However, setting a user parameter in FME Desktop is impossible with the name 05-700-FMESERVER... Which is bothering when you want to test your workbench locally before to publish it.
Harmonizing the naming convention and constraints would be really great.