Currently I can llGetLink... for key, name and number information from a root script about a linked child prim. A recent project of mine has implemented controlling prims like an octopus. This missing function is QUITE a headache to work around.
Alternatively, allow calls to llGetLocalPos() with a link number argument to provide the same location data to a root prim's script about a child prim.
For an overview of linking prims with LSL see: http://www.lslwiki.com/lslwiki/wakka.php?wakka=Link
Thank you for your consideration.