If you parent yourself to an entity that is moving via position updates then you will eventually fall off/drift away even if you turn your collisions off.

(collisions on)

https://fluffy.ws/u/MKTloX.mp4

(collisions off)

https://fluffy.ws/u/qekTSj.mp4

If a dev wants to see this in action you can goto hifi://longcat and ride the train there