** addons-set2a-test / addons-set2a-control
*** Users with any number > 0 of add-ons, where all of their add-ons are part of the experiment list (see below)
*** disqualified-test / disqualified-control
*** Users with any number > 0 of add-ons, where any of their add-ons are not part of the experiment list. (Or may be disqualified by other criteria such as accessibility, OS, etc)