Great article - pretty funny too! I'm glad to see that the RC system really is helping to decrease the levels of spam seen here on Steemit. I myself have been seeing less spam since HF20 but I couldn't figure out whether it was due to the overall decreases in posting due to the downtime following HF20 or whether it was due to the new RC system. It has probably been a combination of the two, but it's great to see the evidence that you've provided here about just how much a spammer can do until they have to take a break (and hopefully a permanent one at that...)
I think that your idea for increasing the RC multiplier based on the time since an account had previously posted is a step in the right direction! As you mentioned, that would obviously still allow some spam to exist here on the platform, but it would certainly decrease how much they can create at a time.
Hopefully the Steemit team and the witnesses will take something like this into consideration with their further talks about improvements to the platform!