I would say all hashtags together. Based on the facts that notes apply multiples hashtags anyways. Also keeps the "mutelist" (for lack of a better word) understandable.
If you're thinking in queries, you could have one query with the collection of hashtags and blocked accounts. (From top of my head.)
Think about it like this: the hashtags are large-scale dragnets to fish for possibly interesting/categorized notes. But whenever someone I follow, boosts a note, then it is essentially "endorsed" by a first degree connection in the network (graph).
So I would mute certain repeating notes, e.g. bitcoin "whale alerts", but I would want to see the special alert that my contact boosted.
I know, you prly got the point already, but still.
