Great writeup! Planned doing the same thing Herr in germany. Thought a Smartphone camera would be enough but there no way to access the camera2 api for those highspeed recordings. I took 1h long 240hz 4k vertikal videos (out of the Schwebebahn in Wuppertal) which could be displayed by MacOS preview. Right no im waiting for a good gaussian splatting tool to create the driving of the "Train” in Blender. The newest Lingbot-map is unfurtunatly not really trained for sideway movement. I always asked myself if the sideway movement and the Parallaxe would make way easier to infer the distance and the 3d scanning capabilities because the pixel only really move one as long you dont drive turns