Whoa this entire post regarding the RAM is the rabbit hole I went down today and posted about here.
I have a set of 8GBx4 on the way and that Crucial set of 16GBx2 you mentioned that might be or might not be dual rank.
Whatever ends up being dual rank is what I am keeping, I am sure a 5900x’s memory controller can handle 4 sticks of memory.
Great write up @HRose