For requests like that, I would always suggest, to not just explain WHAT you want, but also WHY you want it.
At the moment, feed blocks (all of them! Pages, Commerce, Gallery, Blogs …) only load a few entries and then for the complete list of the content you go to the actual listing view, e.g. the forums itself. What’s your use case where it would be useful to go through all content of a specific type within the block itself?
(Just asking to improve the feature request. I am not against it.)