michelangelo3's comment-post-ratio I would very much like to see,

I also like this one. I'll definitely see if I can incorporate it.

I like this, too:

when I am logged in, it would be nice if I could see how many times I have already voted for the author in the last 7 days (I know it would be a challenge).

But yeah, I'm afraid latency might be too high.

Longer term, I'm thinking that some high latency metrics about active authors could be collected by a supporting python script and stored in custom_json transactions from a designated account in order to offload the latency to somewhere where it doesn't matter, but I'm not sure if that model will work for multiple unique observers.