Add Local Storage as a Raw Disk Mapping (RDM) or Mapped RAW LUN to a virtual machine hosted on ESXi

Following this guide and I have question
https://www.experts-exchange.com/articles/9174/HOW-TO-Add-Local-Storage-e-g-a-SATA-disk-as-a-Raw-Disk-Mapping-RDM-or-Mapped-RAW-LUN-to-a-virtual-machine-hosted-on-ESXi.html

There is a local m.2 drive as a datastore called m2
There is a local SSD  Sandisk 32GB I want to use as a LOCAL RDM

I have formatted the m.2 drive as data-store called "m2"
Do I also format the Sandisk 32GB SSD Drvie as a VMFS Datastore and put the vmdk pointer file on the Sandisk drive and map to it?
OR
Do I leave the Sandisk 32GB SSD Drive alone and create a folder on the m2 datastore and put the vmdk pointer file on the m2 folder.  Does that make sense?

Example
1-putting the pointer file on the m2 datastore created a folder mysandisk on the m2datastore
vmkfstools -r  /vmfs/devices/disks/t10.ATA_____SanDisk_SDSSDRC032G_____________________123125400979________ /vmfs/volumes/m2/mysandisk/mysandisk.vmdk

2-formatted sandisk to datastore name sandiskdatastore1 created a folder called mysandisk
vmkfstools -r  /vmfs/devices/disks/t10.ATA_____SanDisk_SDSSDRC032G_____________________123125400979________ /vmfs/volumes/sandiskdatastore1/mysandisk/mysandisk.vmdk