The article is a decent read, however a few parts are misleading at worst, and incorrect at best.
First, the wear tests and standards for A1/B1-04, A3/B3-04, A3/B4-04, A5/B5-04, are exactly the same. The big difference is the A3/B4-04, A5/B5-04 standards include more stringent cleanliness tests, to better handle conditions found in light duty diesels engines, and one may guess, extended OCIs in gasoline engines.
So if your API SM oil is also rated A1/A5, there's really no need to look for "European ACEA A2/A3, B2/B3, or B4" oils, the wear tests are the same and so are the limits. (Note there is no longer a B2 standard). If your engine requires a HTHS greater than 3.5, stick with A3/B3-04, A3/B4-04 rated oils, but as already mentioned, there's no measurement for reduced wear with the greater HTHS requirement.
And as far as API being obsolete, well then, if you believe that, then consider the ACEA tests to be obsolete too. The fact is, API tests run on various OHC AND flat-tappet pushrod pig-iron engines. And if one wants to test valvetrain wear, a flat-tappet pushrod pig-iron engines is an excellent place to start since of the additional mass that has to be accelerated and the additional spring pressures involved with these masses provide much greater forces within the valvetrain than is typically seen in OHC engines.
And as far as timing chain wear, ACEA doesn't test for it either, so there's no advantage in using ACEA rated oils.
One other point. The cleaning effect of HDEOs is a bit overblown, IMHO. However, depending on the add pack, you might see more deposits in the CC, and especially on the sparkplugs. Not good in a racing engine, and the reason you see reduced detergents/dispersants in racing oils.
As far as ZDDP concerns in a flat-tappet pushrod pig-iron engine, well if it's a broken-in, stock engine, with a mild cam, one would most likely have no problems running an API SM/GF-4 oil for shorter OCIs. The Sequence IIIG test clearly demonstrates this.