Posting an update for posterity. It appears that even with app.normandy.enabled=default [true], as long as app.shield.optoutstudies.enabled=false, Normandy is d

Posting an update for posterity. It appears that even with app.normandy.enabled=default [true], as long as app.shield.optoutstudies.enabled=false, Normandy is disabled. app.shield.optoutstudies is the key controlled by the UI element "Allow Firefox to install and run studies". I've closed the above bug report as it's not really a bug.