I feel like the microblog feature would be more useful if we could get a separate feed/filter that doesn't include the tags of magazines that you're subscribed to. For example, I'm subscribed to /m/fediverse because I want to see the threads that people post here. I don't necessarily want to see every mastodon post tagged #fediverse, though.
It also looks like we can't subscribe to a tag by itself, without subscribing to a magazine that includes that tag. So yeah, some more separation there would be nice.
Yes I was also thinking along those lines. When you create a magazine you can choose hastags to associate with it, I briefly considered whether you could create a magazine specifically to have interesting hashtags for you - problem with that is you end up modding the magazine and anybody can see it, join it and post.
I suspect what you describe might come later, it feels like a natural progression from what we have now.