Protocol upgrades: A simplified, practical guide

Protocol upgrades in Bitcoin Cash have often been subjects of controversy. I hereby suggest a very simple framework from which people can evaluate which changes are worthy, so that we can all get on the same page next time.

"Benefit" and "Cost" refer to ecosystem-wide, all-things-considered benefits and costs, including but not limited to such aspects as developer retention, capital retention, development cost, network retention, miner cost, software upgrade burden, security, reputation and so on.

If there is no widespread agreement that a change is at least not harmful, its benefit should be described as "uncertain".