In order to continue testing Android data migration to MEP we will duplicate the MobileWikiAppDailyStats schema, it is a large dataset and we will be able to compare directional data trends on Legacy vs MEP (rather than focusing explicitly on event counts). The MEP schema will use the same data fields in existing schema.
Related prior data instrumentations/QA: https://phabricator.wikimedia.org/T281730 and https://phabricator.wikimedia.org/T281001
Also keep in mind errors found in Legacy schema: https://phabricator.wikimedia.org/T268666, still showing up in Logstash.