This is taken from the Victoria 3 sr2.cr2.  I did a search for the first JCM listed, JCMrCollarBend.  To test for sure in Poser you would need to remove the five highlighted lines from the morph itself.  Work on a copy given a different name.  Try the same motion, here a Z rotation, and you should see the difference.  It would show easier on one with a higher ratio (the deltaAddDelta line), but most are probably pretty subtle so I don't know if you can find a higher number.

Dialing the JCM will show an obvious difference, since you are increasing the effect considerably.  The 0.020000 is effectively a 1:50 ratio.  May be hard to see the difference.  A better test may be to increase that line to 1.000000 in the copy.  The result won't be desirable, but will easily show if it is working.

John