Hi,
Well, If the new api doesn't objects but simple classes, then yes, you won't be able to store these reference in a an FsmObject.
for this, you'll need to use soft referencing by keeping a static dictionnary of string acting as keys and the SteamVR_Action_Vector2 class or other classes.
in your actions, you'll use the string key to store and use that SteamVR_Action_Vector2 class. That's how I handle such case, for example when dealing with xml nodes.
Bye,
Jean