Run 1 valve in each pipe mate, so it can breath out, but not in.
And just leave it venting to the floor as usual.
Put the valves anywhere in the pipe run, makes no odds really.

Like said, ive seen cars throw CLOUDS of smoke because purely the 1way valve issue.

And also ive seen cars smoke like a bitch as they was running 30thickness oil, which is stupidly thin
If oils hot, it gets thinner, and 30 oil will easy get so thin it can get past seals and smoke like a cunt.

Easy thing to do if you want to see if its burning all the oil or blowing it out the breathers is vewnt the breathers into an old water bottle or coke can, thats what id do.

But personally id bank, esp as you can see it, that 99% of it is blowing past the rings or valve stems as the oil is too thin, 30, and the crankcase can currently breath in as there nothing stopping it, which makes the same blowby situation worse.