So some RL supplied AML files actually have the root rotation command in them. But there is a syntax error keeping them from working. I'm still wishing for a menu option to enable this for any motion added from the content manager, but also would like to thank Reallusion for putting the commands into the AML files.
The error is that the command' "<AlignOrientation>true</AlignOrientation>" needs a slight change to, "<AlignOrientation>TRUE</AlignOrientation>". :)