I noticed something interesting recently that might relate to a service install. My WU is going too slow on my machine, so I was going to quit and see about a smaller one. Since I was running the CLi, I just closed its window. The interesting thing is, the CORE executable kept running; and it's still running!

Hidden!
I don't know if the core will stop when it finishes a WU or not; I'd let you know, but it will take about three more days.
P.S. About copying a file, I imagine one could redirect STDIN to the program from a file. But I haven't tried that, either.