My son was one of the reported 228s earlier (much earlier!!) in this thread, I’ve just looked at the thread again because I was curious how many 228s there were this year. The fact he got one answer wrong in CR and that the other one in this thread who reported 228 got a couple of questions wrong makes me think they weren’t any more perfect 228s than usual, because they obviously had the opportunity in those two candidates at least to score more harshly if that were the case.
My son did no prep for the new PSAT other than taking the sample test provided to get a feel for the new test and previously doing some sample tests while studying for the SAT in his sophomore year. He got a 237 in his sophomore PSAT too with no prep course so obviously just a natural test taker.