In your last paragraph you say the front oil boss is for dry sump. Yes you could use it that way, if class rules allow. You say that in front oiling, that all the oil is from one feed, unless you pull the oil off before it gets to the main. Well you have Sanborns notes. You pull the feed out of the filter area. That is before the mains.
Every part of the motor is from one feed. The problem is the distribution. I don’t understand how you don’t see the issue with
#1 main, but you understand how the grooved journal camshaft cause main bearing failure. Its the same problem. A small
Diameter feed passage off of a main bearing,
Trying to feed a galley full of leaks. That main never gets full pressure. 1 main is trying to feed the entire lifter galley from a 9/32 feed passage into a 1/2 passage full of lifter leaks. The oil speeds down the passenger side galley trying to keep up. That is the heart of the problem. Plugging that galley stops the majority. Front oil probably evens out the pressures. But no way it can’t go to the mains because high pressure goes to low pressure.