How about just the latest post from each? That way you it's like reviewing your following list but with their freshest content.
Discussion
Would also like to see making subset lists of users easier to satisfy the circles/aspects use case.
The last post could work but I feel like I would be missing a lot of content, since most users tend to post a few times about the same topic in the span of a few minutes
Right, it's more of a heartbeat to know who's around. Unless you're going to gather some other signal like reactions, boosts, comments then ranking is challenging. If you could take into account social proof that'd be awesome.