Is there any way to keep the final value of an animation curve?

In my particular case I have a character that transforms using an alpha blend between two materials and a morph target.

If I animate the material alpha parameter and the morph target weight using the curve editor then it displays as expected. However after animation has finished the values reset.

I've managed to work around this by using an event at the start and end of the animation to start interpolating the value in script (based on the normalised animation position).

But am I missing something obvious in the editor? It seems very strange to me that animated values should be reset after an animation.