i think its worth a try (although you could exclude the bit about being the owner of the domain and removing all content from domain), cause it seems these companies dont always validate the dmca, (e.g. with youtube, they always take the video down even if the request is clearly bogus)
EDIT: i’ll just add that if they respond asking for proof of identity, then you should probably just leave it and not reply (though i don’t think they will ask for that)