i have only chosen addons that, according to mozilla's 'addon compatibility reporter' are all compatible with multiprocess. and i don't even have any non-compatible addons installed. i can confirm that e10s is definitely enabled when checking about:support. however, any time i click enable/disable on an addon, the about:config option extensions.e10sBlockedByAddons will reset to 'true' the next time firefox is started !! why ??? sometimes this seems to reset subtley in the background, and i don't notice straight away. and even when i do notice i have to restart the whole browser >.< what a pain