Existing examples of XML fragments overriding the defaultValue element are of the level leafNode, for example:
https://github.com/vyos/vyos-1x/blob/current/interface-definitions/interfaces-tunnel.xml.in#L209-L212
#include <include/interface/parameters-ttl.xml.i> <leafNode name="ttl"> <defaultValue>64</defaultValue> </leafNode>
It is useful to generalize this to allow embedded settings:
#include <include/accel-ppp/radius-additions.xml.i> <node name="radius"> <children> <leafNode name="timeout"> <defaultValue>30</defaultValue> </leafNode> <leafNode name="acct-timeout"> <defaultValue>30</defaultValue> </leafNode> </children> </node>
This simply requires cleaning up the empty paths left by the override and merging of defaultValue elements.