Inside the Little Plastic Castle

I don't think you can use more than one filter at once. I don't know how typical my use case is, but I have a number of reading filters and everyone I subscribe to is in one or two of them. Then I check them at different intervals (I should rearrange them, actually, because posting frequencies have changed so much). Where I don't want to see all of someone's posts, I use the tag filtering option you describe above, but if I loaded my whole reading page instead of one filter at a time, I'd still see all that account's posts.

I have a politics tag, but as you've probably noticed I post very little about anything these days.