The other thing that I can't quite get my head around is how the weekly post window works. If I post on the thread every day then according to the formula in the OP:
If you haven't posted in a topic in the last 7 days, posting in it adds 1% of your base bump power to the topic's bump score. Deleted posts count against the 7-day limit, but not the topic's bump score.
it would seem that only the first post will bump it, since every subsequent post that is still in the 36-hour window will have up to 6 previous posts in the 7-day window... so no bump?
My phrasing was inexact: when you post in a thread, the system checks whether you minibumped the thread in the last 7 days. If so, there is no bump effect. If not, you minibump the thread. But separately, at bump score calculation time, minibumps from now-deleted posts are not counted, even though they will continue to count for the 7-day window.
It sounds like people really want a "do not bump" option, so I'll probably end up adding that.