You know how when outside of an atmosphere, the flamey exhaust(s) of the rocket engine(s) extend wider than the engine (and in many cases the entire craft)? That's called underexpansion, kind of a weird naming considering it's basically doing the opposite, but hey. Anyways, onto my thing.
I need to make it so that one of my rocket engines always has this effect, let's say, up to 5 kg/m^3. Modifying many parts of the rocket engine (size, chamber pressure, nozzle length and throat, and maybe more) will affect how this effect is applied.
I have access to XML, so feel free to give values that are otherwise unobtainable in standard part stat editing.
@ChalxAerospace yes, but there's a difference between XML editing on mobile and modding on a PC. I have both mobile and pc versions of the game, and what's possible on one is not possible on the other. Mobile users can xml edit most things but only as far as the game itself allows, while PC users can literally rewrite the game itself to allow for more editing