Gary, ain't pickin' on ya, but let's not blame the system for hot oil. Long idle and taxi times are just another design point for cooling systems.
Airplane and I spent 16-years based, flying, and operating out of the hot southwest with more than 2,500 hours flying there.
I did not have issues after the initial problems and fixes 24-years ago. There are limitations that I am well aware of. IF I am complaining about high oil temperatures after a long taxi at OSH, there are going to be a lot of others in worse shape than me.