Agreed. Especially given that these rate limits seemed to be aimed at stopping something catastrophic like spammers using 100x allotted capacity, a 2x innacuracy shouldn't really matter. The solution was interesting, however, and I could see it being useful in a situation where users are expected to run very close to their rate limits. For example, I could see AWS being fairly careful about not letting anyone use more than their allotted compute/network bandwidth because getting double bandwidth without paying for it is a pretty big deal.