Bitcoin block hashing protocol is constructed in such a way that it allows to artificially craft, prepare and reuse some data, gaining 20% mining performance boost. Technical details:

I used to think of SHA-256 computation and bitcoin block header preparation as of separate tasks, why would you mix them? Well, if you economically incentivized — you would,

And an interesting consequence: if some proposal is preventing this performance boost (even as a side-effect), you are incentivized to block the proposal,