Discrepancies in information on LA and Magnum series oil gallery plugs

NC Engine Builder said
I do not know why your plate has that relief in it. What I DO know, is the galley behind it, has full oil pressure, in fact the passenger side galley is fed directly from the oil pump, and if you look, you will see there is a passage drilled down to the #1 main, and then a passage drilled up from the #1 main that feeds the entire driver side lifter bank. If you leave the plug out, you will dump all your oil pressure out behind that plate, and you will cause a massive leak. And I must be the odd man, I've been doing this for decades, and I've NEVER torn down a smallblock that didn't have those plugs, UNLESS it was rebuilt prior.

What you wrote does make sense, I’m just trying to connect it to what I am seeing here. The previous owner blew the head gaskets in it but there was no signs of oil issues. He could have skipped installing the plugs either accidentally or intentionally. I don’t talk to the guy any more so I’ll never know.
I do see how left unobstructed, too much oil would probably flow through that diverter, at least a lot more than the chain actually needs. Maybe if the thrust plate were like the one on the 318:

I do have the plugs in the core plug kit.
How about knocking the plugs in but drilling a small hole in the one behind the diverter….?