I see another benefit for this bot that you haven't discussed yet. It is also kind of a flaw with the promotion.
On both bots, you mention that a post can only be resteemed once. This is true, but it is once by each bot. It would be a good strategy to get the most out of these bots by using them at different times. I haven't done the analysis, but I would be willing to bet .05 SBD that over half of reblogger's followers also follow resteembot. So using them at the same time means that your post is still seen by the same many of the same people.
I was wondering that myself, how many followers are unique on each platform.