You will find that the first one is selected and disabled when you target ReFS volume, so you can't touch that one anyway
Apologies for a bit of a necro-post. Based on the guide here: https://helpcenter.veeam.com/docs/backu ... tml?ver=95
It's implied - as stated above - that the "Align backup file data blocks" is grayed out and checked. This is true if you look at the properties AFTER it's created.
Further down the page under limitations it states:
When you pass through the New Backup Repository wizard, the Align backup file data blocks check box will not be selected.
I submitted feedback that they should have this at the beginning with the screenshot. I know myself and a few others in this thread were thrown off by the lack of checkbox when creating a new repo on ReFS.