By default, Filespooler doesn’t do anything special with the output from the commands that fspl queue-process executes. If they write to stdout or stderr, you’ll see this on the controlling terminal or wherever you have piped or redirected it. Since fspl queue-process, by default, will process as many jobs as it can with each invocation, this may result in the output from multiple jobs being concatenated together. In some cases, this may be undesirable.