RSS hooks missing from wp-commentsrss2.php

I’m trying to add a basic feed tracking to a plugin using hooks to run the tracking function (but doesn’t echo any output to the feed). The following files: wp-rss2.php, wp-rss.php, wp-atom.php, wp-rdf.php all have the appropriate hooks in them since WP 2.0 – do_action(‘[rss2|rss|rdf|atom]_[head|ns|item]’) but wp-commentsrss2 does not. Is there a reason for this? Would there be an easier way to hook into all the types of feeds?