From a game theory perspective I can only imagine that the winning strategy would be to take the 10-20% hit for three 10 day periods, rather than risk the prospect of being nailed for the full month
I had tried to balance it. The original participants who asked for the 10 day payouts risk getting not re-enrolled for the remaining two or one term. They also have shorter windows to make enough quality posts.
Btw, that scheme has a bonus at the end which means they may not have to suffer any hit.