You should be able to delete all the targetGeom channels, or just selected targetGeom channels using MAT Pose Edit, but I would not recomend doing this on the original cr2's, as you will lose the ability to inject morphs. The deltas can be cleared from a character loaded in the Poser document by the application of a pz2, a pz2 to do this is offten called a "REM" pz2. I should have thought that files to do this would be included with the Victoria 3 distribution, I don't have Victoria 3 so I don't know for sure. The syntax to remove the deltas from a targetGeom channel is:

{
version
        {
        number 
        }

actor ActorName
        {
        channels
                {
                targetGeom MorphName
                        {
                         
                        }
        }
}

I usually create these files in a text editor. If you like you can use a pose file saved from the Poser interface and using "Include morph channels...", then import it into Morph Manager 4 or MAT Pose edit and delete all the channels except the targetGeom (morph) channels, then zero the remaining cannels. This should give you a file which is a good basis for your REM pz2. Now in a text editor you can paste the bit highlighted in red into each channel. Perhaps there is a better way to do this, but thats how I would do it.