Crontab is fine for scheduled jobs. We put them in script files and call them from crontab (crontab -e to edit them).
However, if you want to run a job while you are running another one in Unix, you could use the "at" command with os-command no-wait. This means that the spawned session is not connected with your session at all and killing off your own session will not affect the new one.
I'm not sure if a simple os-command mbpro will survive a kill -9 on the original process (I've never tried it), but using "at" will ensure that it will.
However, with Unix, the spawned command will be non-interactive. If you use os-command under Windows to set off a new session, the session is on screen and can be interactive. If you use character on unix, however, I don't think you can spawn a separate interactive session.
But, it's fine for things like printing reports or labels while you are doing something else. So, if you had a program that neded to print 150 labels and the label printer behaves like a dog and can only accept 10 labels at a time without falling over (Unrealistic? Not on one of my jobs) then you could use "at" to kick off the label print program in a separate session while your main program continued on its merry way, rather than having to wait for 10 seconds after each batch of 10 labels.