He mentions several other proposed cases but ends with Please notice that none of the suggested cases in the list above passes the following congruence test: in Finnish, an adjective attribute (almost always) complies in its form with the noun, e.g. isossa talossa, isoilla taloilla etc. That is, the case (and number) is expressed both in a noun and in an attached adjective attribute. And none of the proposed cases can take such an attribute, so they are more adequately regarded as classes of adverbs or as other constructs than cases.
no subject
That reminds me of a page I read a long time ago where Jukka Korpela talks about Finnish cases.
He mentions several other proposed cases but ends with