Hello Greg,
The namespace are directly associated to the package.
At this stage I have not foreseen to change it.
The Xml annotation are quite experimental.
For the @XmlTransient, I have used them in the case of many to many relationship
Form the
#if($addXmlBinding)
#if($isMasterRelationship)
@XmlElement (name="$i18nUtils.singularize($childrenListVariable)")
#else
@XmlTransient
#end
#end
You can force the fact of being a master relationship by enriching the entity
Ex:
<enrichment>
<entity name="TAG_ITEM" master-relationship-field="ITEMID"/>
Unfortunately you wish the opposite (Change a @XmlElement relationship into a transient one).
There is not this facility available.