Linux hardened repository settings

In Veeam V11 when creating a linux repo where we didn't want immutable backups/hardened repo to be activated right away, we chose Direct Attached Storage and after that Linux as the type of server to use as a backup repository. We also unticked the boxes for "Use fast cloning on XFS volumes" and "Make recent backups immutable for X days".

Now in V12 you have to chose between "Linux" or "Linux (Hardened repository)" when choosing your operating system that will be used as a backup repository. We pick Linux hardened repo as this repo will be used as an hardened repo in the future, but in V12 there is no check box next to "Make recent backups immutable for: X days" as it was before. Which of the following will setting 0 days on Make recent backups immutable for result in? - 0 days equals no backups being immutable, the same as unticking the box next to it in V11 - 0 days equals backups being immutable forever Or do we have to create a non-hardened Linux repo in V12 for backups to not be immutable?

The goal is to have no backups being immutable when setting it up and later on to activate it.

Hope this makes sense - Thanks in advance!