A patron's opinion would be worth wayyyy more than your free opinion in a forum (even if its f95) for a developer, this makes more sense.
F95's member forum opinion is still worth something, sure, but it surely not comparable to someone who pays and support his work. For a developer, F95 works as an awesome type of advertising for their game, if you are happy with contributing and you want to give proper feedback, go ahead and donate, anything else your criticism would be barely a drop in the ocean.