005_Thruster_Changes_Notes.xml alters the behavior of the Thrusters, giving higher-level Thrusters a higher max_force at the expense of higher power_usage.  Please note that Thrusters do not use "power"- they use Thruster Power, which is a seperate variable entirely, but gets referred to in the same way (which is confusing, but oh well-  at least when you look at Powerplants it's not confusing there).