As per my query above,does the vault drives appear as part of disk selection when creating a Pool? Please advice. Thanks
Unity picks disk automatically. There are some discussion on this topic already happened.
Example : Unity Drive Selection
Vault drives will be picked last/when no other eligible drives found.
Yes, you can select vault disks and add them to pool.
Those drives are now only the OS/services drives and can be added to the pool. The vault is now an internal M2 SSD in each SP.