running a UD pulley he should contact the people who have installed them on engines for years and seen the long term effects, like Kyle and Greg DuPree for example. Their experience trumps any single oil test. Plus talking to them is free and fast.
To really be on the safe side, somebody who obsesses about engine wear with a turbocharged car should probably just get a boost controller that they can turn down to ZERO. Or leave the thing in the garage.