Schemes proposing to pay with difficulty / hashpower to change block size should be avoided.  The miners incentive has always been fairly straightforward - it is rational to deploy new hashpower as soon as you can get it online.  Introducing the concepts of (a) requiring out-of-band collusion to change block size and/or (b) requiring miners to have idle hashpower on hand to change block size are both unrealistic and potentially corrosive.  That potentially makes the block size - and therefore fee market - too close, too sensitive to the wild vagaries of the mining chip market.