for reference, the effective glue strength = SOP strength x DOP strength is summarised as below:
SOP strength DOP strength Effective strength (SOPxDOP)
============ ============ ============================
undefined any value DOP value negative: unbreakble
DOP value positive: increasing strength
negative any value unbreakable
positive positive SOP x DOP
positive negative SOP
I'm not a techie, got no proof, this is just by observation on a sample scene by f1 in thread below: