NumCores should be set to a positive number (i.e. number of cores), unless you want to reserve 1 or more cores for other processes.

From what I understand, multicore is only available in train mode for WFO and R-packages. Multicore uses command line, but not the other way around.

I don't have the Z1 source code, so I have no clue about it's settings. Maybe JCL can answer that question?