Does ESXi 6.7 U1 have better performance on 4Kn than 512e drives and how much better in performance?
If you are using 4Kn drives in esxi, are the virtual machines running 4Kn for the virtual disks? If virtual disks are 4Kn, does this mean Windows Server 2008 R2 is not supported as a guest OS?
If you are using 512e drives in esxi, are the virtual machines running 512n for the virtual disks?
There is no RDM (raw device mapping) support for 4Kn drives at this time but I don't think this is an issue at all.
FAQ: Support statement for 512e and 4K Native drives for VMware vSphere and vSAN (2091600)
https://kb.vmware.com/s/article/2091600
"In other words, even with 512e sectors, it is still preferable for the applications and the OS to perform 4KB aligned I/O for predicable performance. This is a general problem and not particular to any specific OS."