Many thanks for looking into this, cartokurtis! I had hoped I had a longer version of my favourite Crystal Beach Cyclone. But with a motion rig it's like with VR: Once you started with it, you can't do without. :-(
And thanks for your offer, but it would be no use, as I load NL2 only sparingly and rather focus on the FS2020 SDK.

Hey Venom. The train creator told me there is no telemetry for the custom kit. I'm super sorry, I have not worked with telemetry servers. However, if you want the park unlocked to study/see my forces and what not, I can do that.

Indeed, problem solved! I'm not good in walking, so I fly over the car I want to sit in and press E.
But now I noticed a new problem: No telemetry output. Whenever I connect the motion rig's interface, I feel a slight rumble for 1 second, but that's it. I crosschecked with other tracks, default and custom, they have telemetry output. Any idea?

Hey, Venom. You have to fly/walk to the train and then press E. I typically set my park to ride first, but these are custom trains set to an invisible track so I believe that is why you cant

Stupid question: After launching your track, how do I get into a car (ride view)? I usually use 'E', but that doesn't seem to work...