Stop is a good idea. The info I have says a stop is helpful but not essential. Personally, I would prefer that extra protection and I was planning on testing a stop anyway.

The website below talks about the ONS system, after a lot of other dribble. It looks like Joel Rensink has another very simple system called 'First Strike' (find with google) that I might code just for practice. I have some other info on ONS directly from Krutsinger, though I have never done a course with him or really followed any of his work. I am just happy to finally test it accurately. Ditto with all the other stuff I have tried but without WFO. Very interesting development tool.

http://www.infiniteyield.com