One use case of overriding is that the logs could have imposed ACLs for users that no longer exists (e.g. the application ran on an old cluster). In this case the ACLs are essentially outdated and it would be good if there exists a way to read the logs.

I see, is this what you're suggesting?
(1) HistoryServer sets `spark.ui.acls.enable=true` - override all application security configs
(2) HistoryServer does not set `spark.ui.acls.enable` - just honor the application's preferences.
(3) HistoryServer sets `spark.ui.acls.enable=false` - override and disable ACLs for all applications.