Standard impersonation reports do nothing. Will reporting a private fake account as "Under 13" work?

Hi everyone,
I need some advice regarding Instagram's automated reporting system. Someone created a fake account impersonating a close friend of mine. The scammer is using my friend's exact first name, last name, and profile picture, but the fake account is set to private.
We have already submitted multiple impersonation reports through the app, but Instagram keeps sending automated replies saying the account doesn't violate their community guidelines. It's incredibly frustrating, probably because the account is private and the system can't see the posts.
My question is: Does mass reporting a private fake account for being underage ("Under 13") actually work better? I read online that it triggers an automatic safety lock and forces the owner to upload an ID to unlock it, which the scammer obviously won't be able to do.
Has anyone successfully used this underage reporting method on a private imposter account recently? I'd really appreciate your thoughts and tips!