I need to try a different approach to this...Will it provide better thermal than MB511?
Your 9700K isn't thermal throttling, and unlike a Ryzen 3000 cpu, it's boost clocks aren't affected by thermals, so why the push for better thermals?
Your 2080 isn't thermal throttling either, but it's boost clocks are affected by power and thermal headroom, but it's not like you'll magically gain 50fps dropping from 75C to 60C... so why the push?
Why the push?
IMO, NO, you don't need to change anything. But if you really, REALLY, want to do it anyway...
To get some of the lowest possible gpu thermals on air, then going by some of the chassis reviews Gamers' Nexus has done than the first 10 on these lists:
[These are out of the box thermals, and those measurements are done in deltaT over ambient, it's not the exact temp, BTW]
I posted 2 lists, because they've done so many chassis tests that they can't post them all. The first 10 are all you really need to take note of.