Here goes nothing.....
You guys are deep into the More's Better theory.

You know, if some is good, more's better and too much is just right!

At least take the time to read the Joe Gibbs literature on Diesel oils. His point is, the extremely high detergent levels in the oil for diesel engines makes it harder for the ZDDP molecules to find a place to stick to. So you can have all the ZDDP in the world but if it can't find a surface, it doesn't do a lot of good.
Several years ago on this board a member detailed an experience with Diesel oils and lubrication failure on a new extremely high output engine. Most pooh-poohed the story, but he had no reason to lie about it. Maybe there is a hidden weakness in the Diesel formulations.

I think that the "use Diesel oil" theory is an article of faith among the believers and expect that its believers cling to the idea out of a religios fervor. Maybe it's time to open our eyes.

R.