OK, if you want to control a morph from a single rotation it’s fairly easy - set the morph to 1, and the rotation to the value you want to match the morph at 1. Right-click on the tab for the Property Editor pane (this will work even if the pane is docked behind other panes, as long as the tab is accessible - that’s a good thing as, for a morph-heavy figure, the pane can take a long time to refresh if it’s visible). From the menu choose ERC Freeze. In the dialogue, under Control property selection, you want to pick:
Figure Victoria 4
Node The bone with the rotation you ant to control the morph(s)
Property The actual rotation
then under Freeze properties you check the morphs you want to be controlled. Just click Accept and then if it works go to File>Save as>Support Asset>Morph and save out the new JCM.