However I have been unable to find any objective peer-reviewed study to support the idea that lowering SAPS from A3 levels down to C3 levels increases gasoline TWC/GPF catalyst lifespan in practical use. The only experimental study I could find on the subject is a
2017 paper by Bernardorff et al., which indicates that a vehicle that consumed 9kg of full-SAPS oil (1.17% SAPS content) did not incur any impaired function of its GPF cats—and less than half the deposited material in the cats came from the oil. The rest of the cat poison was from other sources, such as wear metals and fuel. That study speculated that a mid-SAPS oil "could" also "satisfy the durability requirements of a GPF equipped engine"—not exactly a glowing endorsement. Seems to me, you could actually clog your GPF just as fast with mid-SAPS in a gasoline car if the oil sacrifices wear protection to such an extent that any reduction of SAPS poison from the oil gets made up for by an increase in wear metal poison going straight from the walls of your engine into the GPF.
However I'm sure I know less than anyone else here so I'm curious to know what the research shows.