@an3k Please don’t confuse my need to convince you that you were wrong (which needed to be done in this case in order to get you to solve the easily solvable issue you are currently facing) with arrogance. Arrogance (by its very definition) would be say, ignoring my helpful advice in spite of it working exactly as I claimed, just because it would require one to admit their initial theory was incorrect, even after posting their extremely common optimization issue in this very thread and being told exactly how to fix it by multiple people… 
Consider me wry, smug, snarky, even rude if you must… but please, do not project arrogance upon me.
I have given you a couple hours of my time today so I am here for you, with a common goal. I want to help fix your CPU spike. I know telling someone they are wrong is not a great approach… especially on the internet. But in this case, since you must do your own configuration, we both have to be on the same page in order for ME to HELP YOU. And in this case, that involved convincing you your initial theory was incorrect. Awkward… but it is what it is. Focus less on perceived slights because you may not like my tone, and more on the fact that I am bending over backwards, writing detailed posts specifically for you, pertaining to exactly how one solves your specific issue. Please remember, by following my advice you have begun to see your issue get quelled. I’d say, in spite of what you may perceive in my tone, the proof is in the pudding. I am helping you fix your problem… and your complaints have to do with how you perceive my tone, not with the quality of my advice… and said advice is quite literally and verifiably how one solves your specific issue in MSFS, at least in its current state.
Considering you have been skeptical from the start, and I knew that because I can read, I have had to try and break through that skepticism in order to help you fix your issue, and that continuing hurdle has caused me to drop some niceties and pleasantries as we continue to chat, because, I dunno… a little gratitude would have gone a long way by now.
The thread linked below is a gold mine for optimizing your system when it is CPU limited. Before I read it, I really thought things worked the same way you seemed to think they work.
For 60 FPS, things work the same as described in the linked thread, but you want to tune for around 15 ms instead of 30.
By following the steps in this and subsequent posts, I now get smoother performance than I ever did before, and my PC is a potato compared to yours!
With your setup, you might not even notice the lower fidelity, as the sim looks beautiful and often enough, photo real well before LOD settings get maxed out.
Here is a link to the key post, but the whole thread is full of gold.