Ok. Got it. Didn't remember about turbulence. Looks like the modding of top-lid is likeliest option in my case ;)
About NH-L12S... Currently I have i7-7820X, of course delidded. Currently it cools by Dark Rock 4, OCed to 4.3Ghz all cores, stress-test temperatures ~80C. I had NH-L12s on my ryzens...