The kobuki base by itself does not drift, so it makes sense that the tilted inertia will cause the drift. Of course I can hack my URDF using a weightless superstructure, but I planned to repair this in a far more sensible way. I attempted all I can contemplate, and https://www.uk-exhibitionstands.co.uk/product-category/pop-ups-and-banner-stands/pop-up-walls/