Jim, Trivial? I'm not sure what your definition of think trivial is, but vapor locking and loosing engine power from a heat soaked mechanical fuel pump is not "trivial" in my book.
You are right, that is not trivial. I am not sure what setup you have but I would be more concerned than just adding louvers if that is the issue. You may have something else partially plugged or not working correctly.
From the beginning I have heard of many people with issues of high oil temps and I was one of them but after a little work I was blown away at the improvements I saw.
I have climbed out of the hottest airports in AZ in summer and tested my plane so I do know it works.
I would be interested in the CHT's you see and oil temps.
I have cut off the baffle that covers the front of the #1 and #2 cylinders and then sealed every little tine hole in the baffle, between the cylinders and made sure the rubber matches up very tight against the top cover.
Tim Olsen has some good pictures of this process:
http://www.myrv10.com/N104CD/maintenance/20061022/index.html
Also, you may want to consider insulating the bottom of the tunnel where the fuel lines run in the fuselage and the front of the tunnel along the firewall. You may be heating up your fuel at that point.
Before doing all of the above I was ready to purchase new oil coolers, new louvers, ect.. Now, my CHT's rarely see 400 F and if my oil temps go to 215 even on a 100 deg day climbing out, I have to really be pushing it hard and climbing below 100 knots. On the hot days I just climb out at 105 knots and everything stays nice and cool.
Hope that helps.