Native external sender callouts on email in Outlook

Hi all,

I want to test this feature on individual email addresses before I enable it for our entire domain.  Does the Set-ExternalInOutlook cmdlet allow for this?  In everything I read online, I can't find if this is possible (I can't find a parameter to enable individual email addresses, and not the entire domain).   I only see the parameter to exclude addresses (AllowList).  Please confirm.  Thank you.  Others have asked this question here, but I don't see the answer.

Also, some people in the previous comments (starting with Shark_IT) argue this feature is not beneficial.  I disagree.  Our users often receive emails purporting to be from our IT Dept. (from me and my team).  (They get past the Office 365 mail filter and have spoofed sender addresses.)  And our users ask us if those emails are legitimate.  If those emails were marked "External" our users would know they are not from us.  Granted, there are ways to figure out that the email is fake (but many of our users don't spot the easy clues).   We are trying to train our users to spot fake, malicious emails.  But this feature makes it much easier.  We don't ever have any fake or malicious emails originating internally.   What is the harm?  I don't see any downside to enabling this new feature.

-David