I love "qualified" answers--which exclude actual use of the product. They miss the key point -
Experience with the product.
As for lawyers -
That should help----
if the lawyer has a background (actual experience) in applications of oils -with THIS particular engine .
FWIW I have had a few of the MVVS/ Evolutions -which came with the recommended oils and that is what I used -and even with the thrashing I gave em - they continue to run well - no additional bearing clearnce (how do I know?) -easy you record and compare prop movement at TDC hot n cold and th pistons are smoothly polished in viewing occasionally when changing to another model.
The factory advice has proven to me , to be spot on.