@a.nowodzinski pinged me. I tested this, and it works splendidly.
Full review plus how Drupal would use this API at https://www.drupal.org/node/2510380#comment-10522410.
Text from there quoted here:
Good news! @oleq notified me that he has a proposed solution ready for testing at http://dev.ckeditor.com/ticket/13885#comment:5. I worked on updating the above patch to use the new API that his patch adds. And it indeed allows us to simplify the code here, *and* not pretend the CKEditor <code>link</code> plugin is present.
Note this is a future interdiff, that we cannot use until we update to CKEditor 4.5.5 (see #2321583) and until that fix is actually <em>committed</em> to CKEditor 4.5.5.
So, hurray, this will become more maintainable with CKEditor 4.5.5!