I'm not arguing about the possible advantage of using a 4-minute engine instead of a 5-minute engine. I'm only saying there is no point complaining about engineers pushing the limits of the rules. There is no rule saying that the engineers should be "polite" and not try to push the limits. Indeed, there can't be a rule like that. Pushing the limits is what engineers get paid to do. You can set the limits anywhere you want, and engineers will design products to push those limits, because racers wouldn't buy products designed by "polite" engineers -- racers want to win.