I don't know if you guys have seen it, but in Bitcoin some people have proposed a system for changing the blocksize cap dynamically that mimics what happens in Monero, but instead of paying through a reduction of the mining reward, the miner that wants to mine a larger block has to do it in a larger difficulty. So he should calculate the probabilities and sort out automatically whether it's worthy for those extra fees.

Has this idea been studied when the developers of Monero (or CryptoNote, I don't know), decided to implement the flexcap as it is? If it has, could somebody explain me why one is preferable over the other?

Thank you!