The kobuki foundation alone doesn't drift, so it is smart the tilted inertia will cause the drift. Certainly I'm able to hack my URDF that has a weightless superstructure, but I planned to deal with this in a more realistic way. I attempted all I can contemplate, and all unsuccessful: https://www.uk-exhibitionstands.co.uk/uk-exhibition-stand-builders-for-international-trade-shows/