I would also be in favor of a mixture of the Forementioned ideas. Namely introduce a Stress system for constructs And Energy Management. Regarding the engines, alone a more modular system (as example airintakes, Turbocharger, afterburner using extra boosterfuel, engine Control unit/upgradeable control Software (not Lua just as addin Item top the unit)) that also would diversify industry And might enhance Trade. In Addition it seems sensible to me to reduce weight, especially after ores have been refined.