Hi Mikko,
The batch submission of 3dsmax jobs (which end up as "cmdrange" jobtype running the 3dsmaxcmd.exe command-line renderer), capture everything printed to stdout and stderr, into the .out and .err files found in the job log directory (C:\ProgramData\pfx\qube\logs\job\...)
That said, I just tried running a test using the -postRenderScript option to the 3dsmaxcmd.exe command, using both "format" and "DosCommand 'echo ...'", but neither printed to the stdout/stderr. This test was done outside of Qube, in a command prompt. It seems like the stdout/err of a postRenderScript just gets discarded.
I guess you could open a file for writing, and dump information into that file in the postRenderScript, but I haven't tried that.
-shinya.