An option to trigger a timer block upon hitting 0g gravity would be swell.

Done.

Had this suggested for use on planets, Would it be possible for a version to be used for atmospheric flight if we are staying in atmosphere? So it can try to save fuel when flying, Maybe max out atmospheric thrusters and apply thrust to hydrogen thrusters as needed

So, to clarify, focus primarily on atmosphere and ion thrusters until they just aren't enough to do the job before kicking on hydrogen? That doesn't sound too hard to add in, and would be great for saving fuel. I'll work this in to the next update.

Yes, But for horizontal flight in atmosphere, My old ship relied primarily on atmospheric but it still didnt have the thrust to stay in the air without hydrogen assistance, But it was likely equalising the thrust from each of them in the same way reactors equalise there output

So "not only just for launch, but for normal flight as well"?
If so, that also sounds easily do-able, but seems like it ought to be its own script. Maybe.
In either case, it sounds like a good idea.

Yeah just normal flight, so it will max out atmospheric engines before using hydrogen,

Hey, could you give me (asuming atmo was working to full effectivness as well as hydrogen) a esimate on how much hydro gen per liter per second? So,
A=(not real)100m Atmo works up to this point
B(Also not real) 120m Hydrogen turns on
C=300m(U get jist) Destination
So assuming all you need to do is get from point B to C, how many liters of hydrogen are used per liter of cargo+blocks per second, and how many seconds are between Point B-C, also, speed does not matter because you script does not use drift to save hydrogen. (Should do that so that you stop dead on 0g no brakes)