Ah I see that is a cool idea and I will look into it. As for now next week I will be cliff diving in Greece for 2 weeks, so it wont be anytime soon.

As for solving the provably fair aspect. I decided to use the hash of the first Ethereum block found after the deadline. In the new process when a deadline expires, first the public hash from the server seed will be published in a transfer on STEEM. Then when a new Ethereum block gets found this hash will be used instead of the transaction id and also published in a transaction on STEEM.