I don't quite understand the loophole clearly but as you pointed out, posting too often devalues the users contribution to the community. It seems possible to add this consideration to the reward pool distribution formula. If one post per day ensures the ability to engage, and ten posts make it impossible, then the first has more valuable to the community. Abusing the account system might be an easier fix on it's own. Multiple accounts using the same writing styles could be recognized at least. Seems like a good solution is possible.