Hi Dan,
I assume if the breathers on your newer engine are starting to get more
oil/vapor soaked they would likely exude quite a greater odor when air/vapor passes through them, which maybe is now more noticeable. If so, I assume pulling and sniffing a breather may tell.
Then if so, I imagine you could replace the breathers to give yourself a breather while you consider the other solutions for longer term.
I’m glad you said it’s an 'acrid exhaust' odor and not just an acrid odor, hopefully so. Are you sure it isn’t the acrid odor a wire or something else in the engine bay burning or melting? Also you sure it’s not a header connection leak (although you did say it doesn’t smell like the pipe exhaust and I suppose that would).
Before I added my PCV system, I’d replaced the breathers a couple times as they would get very dark/oily/smelly fairly quickly, with a very strong, pungent
oil/fuel odor after they got bad whenever I opened the hood.
Best of luck with it! Brent