I stick a cardboard bike box inside a padded bag and stick pipe lagging on the tubes, rotors off etc. Short of a reinforced hard case, nothing is going to save the bike from a proper, cataclysmic impact that will cause real damage, you’re really just trying to stop bits like mech hangers from getting bent. Leaving tyres inflated adds some padding too.
For road bikes, the Crateworks boxes are brilliant, sort of plasticised corrugated plasticised carbon, but I doubt you’d get a Rocket in one of those tbh. Shame they don’t do a mtb one.
Mostly the issues are bent rotors, mech hangers etc. Serious destruction is rare or this forum would be rife with threads about it.
Going anywhere good then?