Rated 5 out of 5 stars

Excellent addon! It would be awesome if menus could stay open also with the addons 'History Button' and 'Undo Close Tab Replacement'.

This review is for a previous version of the add-on (1.5.10). 

Stay-Open Menu 2.0b2 supports the 'History Button' add-on. Currently available at https://addons.mozilla.org/firefox/addon/stay-open-menu/versions/ or wait for the final 2.0 release.
Support for 'Undo Close Tab Replacement' may be considered for some future release.