Just building off Nigel's comment. You are able to leverage the effects dissolve feature with the State ability of Custom Controls to build a multi keyframe effect.
However like Nigel is pointing out this is using effects dissolve so you have to Spline parameters available.
When your recording a custom Control you can use the insert event - state. This will insert the state of the Switcher. Basically a keyframe of the entire Switcher. You use the memory attributes (in dashboard you see this on the bottom Tab) to defiance which items will be recalled and which items will not be.
This will allow you to build an effect to a similar method.
#Carbonite