Wikipedia lists something called the 'multiplicative case' in its template of grammatical cases. However, on the (stub) article of said case, it lists only two Uralic languages in which it is found - Hungarian and Finnish - but proceeds to suggest that in both of these languages it serves an adverbial role, which it claims causes it to be 'not considered a real case' in either of these languages.
Besides these two languages, is it present in any natural languages in an uncontroversial/accepted way? Alternatively, is the multiplicative case found in any common conlangs?
Other than the Wikipedia article, and the references within it (all of which are simply analyses of its use in Hungarian and Finnish specifically), I could find no real original mention of it elsewhere. If it does not seem to appear in any natural languages in an unprotested manner and is essentially unmentioned aside from this one article, why does it warrant being considered its own case, rather than just some quirk of morphology (at least, naturally)?