Morphing sounds in keygroups?

Is it somehow possible to morph sounds by changing the volumes of different sample layers in a keygroup?

I would for example like to use the modulation or aftertouch parameter to lower the volume of layer 1 and rise the volume of layer 2 in a key group.

This can be useful when layering a piano / string sound and switch between more piano or more string or when using an organ sound (switch between a 'dry' organ sample and an organ sample with Leslie effect.)

have a look at the daydream sound's channel on YouTube. he likes to explore and demonstrates features like this on samplers.

I hoped it was somehow possible on a standalone MPC.

As far as I can tell, aftertouch can only be routed to the filter controls (under LFO Modulation)... you might be able to pull off a trick or two by setting up two different programs... since there is no negative envelopes at this time I'm not sure you could do this. The Force has some macro level programming, and if that type of functionality comes to the MPC then there may be a few other ways to get at a morphing style patch... but at this time I don't think that there is anything possible to do that isn't more work than just setting up two separate programs and adjusting levels on the fly.