Spline controller orientation

[_Aka_]

Hi
After taking a look at your spline, I believe the issue is from the small number of cache points, which leads to the cached tangents not being precise. Increasing the number of cache points will solve the issue.
Improving the calculation of cached tangents for splines not densely cached enough is something I am planning to fix in the future.
Thanks for reporting the issue, and have a nice day