Oh, I actually have learned the answer to this one - at least for the head morphs. Use the lock actor command on the head before applying the pose. I have also read that you can use the memorize figure command to save the current settings as the default. Then if a poses changes these you can use the restore figure (for the entire figure) or restore element, for just the element (such as the head) you wish to restore. I have found using the lock actor on the head works best for me.