So I decided to look into the Turbopack config file, I changed the mesh in the config to the default Atlantis SRB, went into
Orbiter, injected with the scenario editor, and guess what? It worked!
Although there were of course problems with the scale (it was almost as larges as a DGIV!), I could still pick it up and fly.
Also, it didn't replace the stock Turbopack, which is a big plus.
So this discovery adds new possibilities for custom Turbopacks, like maybe a Buck Rogers-type rocket pack. I'm not sure if it
would be possible, but maybe this could be implemented into a moon rover type of thing.