I was wondering if you ever figured this one out, knowing that if you did, we would all learn something.
Well I got the burning cup issue to go away. On a whim, I changed oil pump relief springs. I had cut one down, to lower pressure. Pressure was more than enough with the cut spring. 50ish lbs at idle. After I changed spring, pressure is mid 60s at idle. The issue went away. Seems crazy to need that much pressure to stop the issue.
I did have a groove put in my cam. It gets more oil to the top, although not a major amount more.
I have a 470 on the stand that will have a roller cam in it. I did the valley mods/installed a restrictor on it to get full time oiling. I'll see how that works.
It probably makes more sense than you think.... now.
IIRC those cups were oiled thru the adjusters or thru a verrry small passage in the arm itself. Liquids are just like electricity in that they will take the path of least resistance. In your case 50 psi wasn't enough pressure (voltage if you will) to overcome the resistance of the passage compared to other sources of escape near by.
