Improved auto-tangents in curve editor
It's time to AE have a better curve editor with an option to auto-clamp and avoid unwanted overshooting and other weirdness.
Blender, for example, is an open source software that has a very clever way to manage tangents automatically.
And the source code for that is... well, OPEN. I know it's not as easy as I think, but having a working code available around at least reduces the "figuring it out" work... it's a starting point.