From his discord post:

Thrusters in space

Cold gas, atmospheric

Cold gas, vacuum

Here is my current progress on RCS thrusters using the previously shown volumetric rendering approach The first video shows hot gas thrusters in a vacuum, these were modeled after real references and look quite different from how they’re usually rendered in games The next two videos show a starship-style cold gas thruster, first in-atmo and then in a vacuum

Thanks to Stefan for providing the references