Ohhh, nice; happy to have a chat on the subject; suggest a messaging option to discuss further if you're interested. Check out keybase on my profile for some listed contact options; you can also use the padlock symbol in the menubar there to PGP encrypt a message to me and share that through any suitable channel that can handle that ascii.
Edit: I've captured and extracted-to-textured-mesh Mirker Bahnhof before it got covered by the scaffolding; if you're going to do another recording I'd highly recommend you include an IMU recording and ideally (though much less critically) a GNSS raw measurements recording that includes carrier phase. I've got a recorder for the latter that exposes a simple USB-serial port that should work great unless the GTW15 windows are EMI-shielding (but iirc they aren't).
Well havent tried to do IMU rading& GPS while doing highspeed recordings. But maybe thats the fix. But also as a goal i would see to do the ICE from Hamburg to Munich as it is the longest with 8h but while 300kmh the 240 fps of a phone isnt enough and a linescan camera would be needed again. And the window (quite literally) is closing as the new ICEs have those New meshes inside so you cant take the Video without those... Also the data requirements of an 8h 4k 240Hz/480hz video are a bit scary