This will be started once the instrumentation is deployed on production i.e. all target wikis (listed here https://www.mediawiki.org/wiki/Reading/Web/Desktop_Improvements#Test_Wikis)
All scenarios and QA status will be reflected in this document : https://docs.google.com/spreadsheets/d/1GtlAas8wBD4-J03nqwZlFaBJ0TYbhv-ORWheho4LCQs/edit#gid=0