OK, it seems WD isn’t really interested to give detailed support to their products.
Also I don’t understand for what the SSD is delivered in the slower and lifetime shorting setting of 512b.
There is a way to change the firmware setting for (physically) sectorsize in Linux.
“# nvme id-ns -H /dev/nvmeXnY”
shows
LBA Format 0 : Metadata Size: 0 bytes - Data Size: 512 bytes - Relative Performance: 0x2 Good (in use)
LBA Format 1 : Metadata Size: 0 bytes - Data Size: 4096 bytes - Relative Performance: 0x1 Better
so there is support for two different sizes 
“# nvme format --lbaf=NUMBER /dev/nvmeXnY”
will set the desired size where NUMBER is the value for LBA Format Code (look above)
That worked for me fine!
Of course the setting is OS indepent in further use of the SSD; the setting is stored in the device itself and keeps resist until you change it again.
!!! You will loose the complete content of the disk after changing the size !!!
