On a serious note to your rankings of the winners (Pennzoil Ultra Platinum & AMSOIL Signature Series scoring well across most testing), I had a thought that it seems as if AMSOIL Signature Series is simply a better version of Mobil 1 Truck and SUV
in some ways; which we have seen has “similar” blending to boutiques (PAO, ANs with AMSOIL Signature Series/HPL having generous amounts of esters)

and another reason many like the ESP lineup as well (which would have been really interesting seeing it tested here instead of T & SUV)
Couldn’t that highlight the key differences in modern oils being more towards their top treat and additive package for end goal results, rather than base oil chasing? (Looking at Valvoline Restore and Protect and its additive doing the piston deposit cleaning, while knowing it’s not an extended drain oil)
Of course, amounts of each type of base oils that get blended is anyone’s guess, but we are aware there is even more import these days to the rest of the oils overall formulation rather than simply chasing base oils. (Unless you really want to extend intervals, and this requires boutiques blending and cost for repeatability & headroom)