Hi Mathias,
That’s not a bug…
I should have clarified - the updated angle goal is still giving numerically correct forces when using real Young’s modulus.
Since the strength depends on the cross section, this does mean if you scale your model by X, you’d need to scale the angle strength by X^2 to get the same convergence behaviour.
As far as I know, K2Eng still uses the same angle formulation as was in the previous version of Kangaroo, so will converge to the same thing, but slow for large scales, and potentially unstable for very small scales.