Some journals allow post-prints to be shared, but not the publisher's version. In these cases, can I share those proofs that are generated before the paper is published? They are not the final version that will show up on the publisher's website, but are formatted.
I am pretty sure that Proofs of a paper are considered publisher's version. They are definitely not covered by the word "postprint", which excludes any action by the production team of the publisher (as opposed to the editorial team, including referees). Similar terms such as "Accepted Manuscript" (AM, used by e.g. CUP) have the same property: the AM is the paper as it as been accepted by the editors, thus before entering production (and thus proofs are not an AM).
So, unless specifically allowed beyond any ambiguity, you should expect green-OA compatible journals not to allow you to share the proofs on your web page or on repositories.