Struts7 Allowlist Capability

It is recommended enabling the allowlist capability with struts.allowlist.enable.
I added my package names to the struts.allowlist.packageNames.

But I get these warnings (leading to further errors)
WARN  [org.apache.struts2.ognl.SecurityMemberAccess] (default task-2) Declaring class [class java.util.Locale] of member type [public java.lang.String java.util.Locale.getLanguage()] is not allowlisted! Add to 'struts.allowlist.classes' or 'struts.allowlist.packageNames' configuration.
Also for java.util.ArrayList, java.io etc.

Is this really so restrictive?
And if yes, is it ok to add "java,javax,jakarta"?

I found this in org.apache.struts2.ognl.SecurityMemberAccess:
    private static final Set<Class<?>> ALLOWLIST_REQUIRED_CLASSES = Set.of(
            java.lang.Enum.class,
            java.lang.String.class,
            java.util.Date.class,
            java.util.HashMap.class,
            java.util.Map.class,
            java.util.Map.Entry.class

Is this really so restrictive?
And if yes, is it ok to add "java,javax,jakarta"? Or is that too much, so I could as well set struts.allowlist.enable=false?
I am not sure how I identify the required classes (without testing the whole application)
Unfortunately, I did the migration before I set struts.allowlist.enable=true.

Best regards
Ute