index-sort-as question

I'm not sure from the writeup how sort-as should work
in the case of nested indexterms in the map's metadata.

If I want to ignore leading dollar signs in my indexing,
I understand I can say:

<indexterm>$apple<index-sort-as>apple</index-sort-as></indexterm>

I assume for a nested case in a topic, I'd do:

<indexterm>$apple<index-sort-as>apple</index-sort-as>
  <indexterm>$delicious<index-sort-as>apple</index-sort-as>
    <indexterm>$red<index-sort-as>apple</index-sort-as>
    </indexterm>
  </indexterm>
</indexterm>

In the spec, we have the following wording:

 You may specify a global default sort order by placing
 an indexterm instance in a map's metadata
 (map/topicmeta/keywords/indexterm). There, the indexterm
 has no content context and will not generate an index page
 reference. Using index-sort-as there will set the global
 sort order expression for that term.

So what does it mean to have

<indexterm>$apple<index-sort-as>apple</index-sort-as>
  <indexterm>$delicious<index-sort-as>apple</index-sort-as>
    <indexterm>$red<index-sort-as>apple</index-sort-as>
    </indexterm>
  </indexterm>
</indexterm>

in the map/topicmeta/keywords?  For example, does this set 
a default sort order for "$delicious" in all cases, or just 
in the case of the above three-level indexterm?  That is,
is the above equivalent to saying

<indexterm>$apple<index-sort-as>apple</index-sort-as></indexterm>
<indexterm>$delicious<index-sort-as>delicious</index-sort-as></indexterm
>
<indexterm>$red<index-sort-as>red</index-sort-as></indexterm>

in the map's metadata?  

paul