Make a bounty based on stake/post is really worst thing. Just take a look how many of your participants spamming on this forum to get highest stakes with their spam post (Many user even made more than 1.5k posts ONLY during campaign)
I believe bounty manager already know burst posting are not different with spamming. And I believe he will cut off every participants who caught cheat and spamming the forum just for reach as much as post to gain their stakes.
We can wait for the official calculation from the manager.