We are currently oversampling mobile VE events on all wikis, but not mobile wikitext events, which means that we're logging data on only 1/16 of our control group.
We should turn on oversampling for the mobile wikitext editor at our 20 test wikis (T221196). It would be better not to turn it on for all wikis since mobile VE sees more edit attempts than any other editor. I'm sure the Data Lake could cope with the extra data, but since that would mean logging almost a million extra edit attempts per day, better not to ask it to!
This also means we should be oversampling VisualEditorFeatureUse in the same way, but I believe that their configurations are already linked.