Intermittent crankcase pressure issues

I agree with AJ, the heads are flooding. Do you have a baffle In the valve cover to shed some of that oil?

On a whim, have you looked at the rocker shafts thoroughly? You beat the **** out of them with that mistake on their orientation. Could they be cracked? The end caps dislodged? Are they even positively seated correctly now? You said the condition improved after correcting the rocker shafts, that’s a good thing and a sign of the original problem. Could it just be residual oil at this point? A soaked breather is going to have a lot of residual oil that will heat up and leak over everything.

I too have crankcase pressures that are high - it’s the turbos fault with loose tolerances. I run plumbing to an oil separator and drain it off.