New (January 2023) mod that does the same as this mod, in a different way so that it DOESN'T break tank inventory systems, and applies to modded tanks too. Comes with an NPC toggle:
Heavy Gas

Sadly, this mod breaks the ability to refill your bottles from a tank, as it sets gas tanks to have a capacity of 0L.

Is it possible to adjust this to restore tank cargo volume to vanilla values?

Would be nice if this mod had different mass for hydrogen and oxygen ! Oxygen liquid should be about 1235 kg/m3 and hydorgen liquid 71 kg/m3. Anyway, do you have any recommended companion mod, to rebalance the hydrogen tank capacity with this one ?

Thank you for this.
I think gas mass in hydrogen engine is not added, right?

@DEADmetal
iirc when reading MES allows you to set usage and thrust multiplier of spawned NPCs

I don't use MES to spawn NPCs yet as I have not got that far however I did set up
Robot Raider Pods
That requires MES and when setting up the Drop pods it had options to set thrust multipliers. Being as Robot Raider Pods is just adding the Pods and whats not I believe the setup is directly related the MES options for setting thurst multipliers and fuel usage.

If you have any luck let me know @DEADmetal

Hey, I would very much like to make this mod not break the AI (not make them crash into planets and moons because of insufficient thrust for a lot of ships).

For this, I would firstly need the authors permission to modify it. Also, perhaps the author would be interested in doing so themselves. Anyway, I need to contact the author regarding this matter, but I had no response from them. Could you help me with this?

Thank you for updating this with the correct volumes!