Boost - Ignore url variables but still cache the page
i just saw you in this issue :D

have you tried:

2 options to solve this. Create a rewrite rule at the server level to strip userID=1234 or in setting.php strip it out &amp; use hook_boot to add it back in.


  A more interesting solution proposed in this thread by mikeytown
  (maintainer of several high performance Drupal modules like Boost and
  Advagg), is to remove specific query parameter at the server level or
  in settings.php, thereby tricking Drupal into getting and setting the
  page cache using a cleaner URL string.  This will almost certainly
  have unintended consequences, however, and should be implemented with
  extreme caution.


Found here: http://www.asmallwebfirm.net/blogs/2012/07/page-cache-vs-landing-page-performance