… and remove the runtime warning… 
Sounds reasonable. Unfortunately I’m tied to Cannon for I need the HeightmapImpostor (only available for Cannon?).
What about the idea to compose the body with the help of LockJoints (Cannon only) instead of parenting? Although this sounds like unneseccary computing overhead.
Like so: https://playground.babylonjs.com/#PRHF00#17
. J