Attached is the text of an example cr2 to demonstrate what I am talking about. You will need to loose the ".TXT" part of the file extension before you can use it in Poser. The figure is a BODY actor, and two props, named rShldr and rForeArm.

Load it in Poser. First select the rForeArm and give it a negative xRotation. Nothing will happen until the rotation exceeds -80. At -81 the Morph-002 will be fully expressed, and it will be expressed at double strength when the rotation reaches -82. Obviously this expression is way too aggressive. There are a number of ways you can tone down the expression, one way is just to make a weaker version of the morph, but I want to show you another method.

Restore the figure. Select the rForeArm and give it some positive yRotation. This will express a different morph, Morph-001. Nothing will happen until the rotation exceeds 80 degrees, but this time the morph will express much more slowly.

Morph-001 contains some extra slaving code using 'valueOpTimes':

                  valueOpTimes
                        Figure 1
                        BODY:1
                        MorphMult-001

This  valueOpTimes should be the last block of slaving code in the channel. The code points to a valueParm channel in the BODY, "MorphMult-001". You can use the MorphMult-001 dial in the BODY to control the strength (or speed) at which the morph is expressed.

valueOpTimes multiplies the value of the channel it is in by the value of its master. So when the value of the  MorphMult-001 is zero, the slave channel will be completely disabled, and when the value is one, the slave channel will act as normal.

Try adding the same slaving code to the Morph-002 channel.  There is also a MorphMult-002 channel in the BODY, this is not used at present.