Bezier curve takes multiple frames to resolve

[_Aka_]

Its very un-Unity-like for the spline to not be ready to use in the first Update.

Curvy 2.2.4, which should be available very soon (it's right now going through Unity's assets approval process) fixes this. A spline will be ready to use after it's Start() method is called. You can have a look at all the additions in 2.2.4 here https://curvyeditor.com/releasenotes