Working with, around, or against SplineController

[Livealot]

Are there guidelines anywhere on how to work with the SplineController? Besides being consistent with the relative/absolute mode, it seems like there are other steps (i.e., update timing) about how to write code that doesn't fight with whatever the SplineController is doing behind the scenes.

For example, I'm trying to apply an ease-in/out curve to the movement using RelativePosition, and the way I'm doing it obviously is fighting with the SplineController's attempts to set the RelativePosition. 

So is there a guide/example somewhere of the right way to augment/extend the splineController?

Or is there a "dumb" version of the SplineController that doesn't try to apply some default settings, so you can fully script the inputs?

Thanks, JJ