Everyday is a school day!!
I recently asked the vSAN vExpert slack channel the following: “Is there a way to set a default storage policy for a specific vSAN cluster? Use case – shared vCenter server with 10 hybrid vSAN clusters and 1 “private” customer with dedicated cluster running AF vSAN. The Private customer wants to use RAID6 but their deployment method just now does not allow the selection of a storage policy. We can’t change the default policy as the other 10 hybrid clusters are using this (and also don’t have a way to select a policy during deployment).”
Slightly embarrassingly for me that I didn’t know this but Steve Kaplan (@stvkpln) told me how to do it!
If you browse to the vSAN datastore object then Manage then general you can set the default policy for that datastore. Simples!