Does SSO setting ‘Preserve manually granted Custom Roles’

Hi everyone - quick question on the SSO setting ‘Preserve manually granted Custom Roles’ on the Insided platfrom. My understanding is that this is a ‘merge’ setting and does not have a ‘persistent’ impact to role mapping.  

Question1: Example:  This setting is enabled  and say community manager assigns role ‘XYZ’ manually to a user and the same user is assigned ‘ABC,123’ roles through SSO they end up with a merge of the 3 roles  i.e. XYZ,ABC,123? 

Question2: Further say we remove the role ‘ABC’ from our Identity Provider (SSO backend) and the same user logs in next time they should only get manually assigned ‘XYZ’+ sso provided role ‘123’. Correct? Or will the platfrom persist the previously SSO assigned role ‘ABC’ for this user?

Question3: With this setting disabled: All manually assigned Role are overwritten and only SSO assigned roles will be assigned to user after a successful SSO login.

Have a good weekend!