Thanks, Bud. Actually, it works fine as is. I just created the task and use a gesture to run it. Nova restarts fine just like when you press the shortcut in Nova settings under "advanced". FINALLY!! And such a simple solution. Where have you been all these 11 months??!!
Could you try killing it with Tasker but not restarting it in the task? I'm not sure, but it might restart by itself if its set as the home launcher; if so, restarting it manually with Tasker is not needed and could cause issues if its starting it again.
Also, was root access needed to kill the task with shell? I never had a need to do it so I never tried.