Ok, so my post was nuked again (My computers fault) so this will be short and sweet. I have been away, so I apologize for the delay;
Suppose there is a big miner with 33% of the hashpower, and there are 67 small miners with 1% of the hashpower. Because of the Law of Big Numbers and simplicity, I'll assume that they all mine blocks in a predictable order;
BigMiner, SmallMiner[1], SmallMiner[2], BigMiner, SmallMiner[3], SmallMiner[4], .. , BigMiner, SmallMiner[66], SmallMiner[67]
I'll also assume that the rollover fee will be distributed over the next 100 blocks.
BigMiner can assume that it can recover 33% of the lost reward on a future block. So if the BigMiner can mine a block that exceeds T while simultaneously getting a reward that is better than a block less than T, given that his reward is reward - penalty + .33*penalty, then it's at a net positive. Whereas a small miner could only do reward - penalty + 0.01*penalty. What is further problematic for the SmallMiner is that if they mine anything with a rollover fee, the BigMiner will get 33% of the reward whereas they will be lucky to get 1% (Not only is the reward less for himself, but any rolling over reward is more beneficial to his larger competitor(s)). In this way, the BigMiner has a competitive advantage over SmallMiners.
I tried to come up with specific numbers that would show the attack on your algorithm, but I wasn't sure what values you were using to get your graph
1, so I think it would end up being a straw man anyway. The bottom line is that penalties or rewards rolling over hurts the SmallMiner more than the BigMiner. SmallMiners being less able to recover over future blocks.
By "penalties or rewards" I mean that it doesn't make a difference whether you are rewarding the current larger block and rolling a bonus over to future blocks, or if you are penalizing a big block and then passing the difference to future blocks.
I didn't see a response to that problem, sorry if I missed it.
1http://i.imgur.com/EZvlJq7.pngEdit: T was defined as the target block size.
