I want to use the same Tag slug for different Tags.
My URL structure will be unique basing on the category, but post_name and post_tag may happen to be duplicate in some cases.

I need this for good reason, because Tags will be multi-language, meaning that the Tag Violin will be assigned to the Professor (post) of Violin but the same Professor will also have another post, with same name but with Tag Violino, in Italian. Problem is that some Tags are identical in both EN and IT, Piano for example is the same.

Example:
mysite/professor/piano/professor-name
mysite/i-professori/piano/professor-name

I know there is a filter called wp_unique_post_slug and it worked perfectly when allowing same-slug-posts (found here), and I looked up on google for something like wp_unique_post_tag_slug but the latter does not seem to exist.