I regularly hit 250+ with oil cooler
I also don't see the point of running 5-30, I did all last year and saw very little to no improvement since the oil pump seems to cavitate at 5800rpm and pressure drops hard all the way to red line. Watch rice classics video in his "SCCA T4 Build" thread. In his video you can see his car do the same thing, oil pressure is left gauge in the center console.