It will be useful to have different curve response assignable to (certains?) morphed parameter:
i.e. I want to morph gain but I do not want to increase volume so I morph gain goes up while rig volume goes down. it seems that gain is linear while volume rig is a kind of inverse exp (and that is very useful to have it inverse exp), but if I do this during morphing for certain setting the global volume will increase during morphing and finally decrease at final morphing stage.
then assignable curves will allow for more precise morphing.