Honestly if it were to be supported I would much prefer arbitrary numbers of tags over one or two. Okay, maybe it should be limited to avoid an instagram-like hundred-tags-I'm-so-funny scenario, but the ability to tag posts with both general and specific tags would be nice, and many items fit under several specific tags.
This is a nightmare in terms of the simplified non-repetitive tag display I'm advocating here on this same post. (Frankly, I like the simplified display better than arbitrary tag numbers.) Everything's a balancing act.