We don't currently throttle our citation building because we know how Google merges data with their Places index in chunks. We have tested building hundreds of citations in one day vs spreading them out over time and have not found a difference. We don't believe citation velocity is currently something that Google is considering.
That said, Google is getting better and better and aggregating citation data into Places, and this might become a factor in the future. If you'd prefer us to spread your citation building out over time, please just indicate this in the Additional Info field.