You could do the math...
Or you could just move it, and see if it works.
If it knocks easily at running temp and typical fuel and other conditions, you are too advanced.
If you lose power and fuel mileage, you are too retarded.
From what I gather, you might not want to push the knocking envelope too close. You might have harsh engine pressures but be just short of knocking, and not be able to tell it. I don't know about the sources though. It's just something I remember reading or something.
Just go by feel, and hope for the best.
Do the calculations if you wish and compare the numbers against industry standards for timing with similar conditions. However, that may take a lot of research.
As they say, the proof is in the pudding. If it works, it works.
Could there be something wrong, and you not notice it? Possibly. There are risks with anything.
I can say that it will probably be more sensitive to lugging with advanced timing.